Easy Thai-Style Slow Cooker Vegetable Massaman Curry Recipe

If my husband had to pick a favorite weeknight dinner, this slow cooker vegetable massaman curry recipe would likely win first place. Every time we go out for Thai food—and I mean every single time—he orders chicken massaman curry. If you’ve never had it before, massaman curry is a rich, creamy coconut and peanut dish, traditionally made with potatoes and peanuts. It’s luscious, slightly sweet, and has a spicy peanut sauce that’s to die for. I don’t blame him for being predictable because if he didn’t order it, I would!

If you love easy vegetarian curry recipes, check out my lentil kale soup with coconut and curry, this red lentil dal with coconut and curry, or this coconut cashew curry soup.

Why You’ll Love This Easy Massaman Curry Recipe

When I was developing recipes for my book, Fresh Flavors for the Slow Cooker, I wanted to recreate James’s favorite massaman curry recipe but in a lighter, vegetable-packed way. I swapped out the chicken for cauliflower and green beans while keeping the potatoes, which soak up that silky sauce and add a satisfying, starchy bite.

I also made this recipe easier by using store-bought curry paste and cutting back on the coconut milk to keep it lighter but still rich and flavorful. The result? A dish that’s become a weeknight staple in our home (and even made it into the book on page 31!). It’s healthy and comforting, and the vegetables absorb the curry sauce beautifully.

But what I love most about massaman curry is how versatile it is. While the traditional Thai dish often features meat, this version swaps in hearty vegetables, making it lighter yet still incredibly satisfying. Plus, slow cooker recipes really make busy weeknights a breeze. 

How to Make Slow Cooker Massaman Curry

The base for this vegetable massaman curry is made with red curry paste, onion, garlic, and ginger. The aromatics need a quick stint on the stovetop or in the microwave to soften before going into the slow cooker, but you can knock out this step a day ahead. The cooked aromatics go into the slow cooker with canned tomatoes, broth, flavorings (fish sauce, tamari, and a touch of brown sugar), cauliflower, and potatoes. 

Once the vegetables have simmered for several hours and are tender, a mix of coconut milk and peanut butter is added, lending the sauce creaminess and flavor. Frozen green beans are also added for color and brightness (see substitution ideas below), along with roasted peanuts, which are traditional and provide texture.

Pro tip: One of the hallmarks of authentic massaman curry is the slight separation of the coconut oil from the curry paste when it’s cooked. This process adds a depth of flavor that makes the curry richer and more aromatic​. You don’t have to worry if this doesn’t happen perfectly in the slow cooker, but it’s a good sign that the curry paste has fully bloomed in the oil.

Ingredient Notes

Many of these ingredients are pantry staples. If you’re having trouble sourcing ingredients, check your local Asian market or online. See the full recipe card below for exact ingredient amounts and printable instructions. 

Aromatics

• Coconut oil: Provides a rich, subtle flavor and helps to sauté the aromatics, creating a flavorful base for the curry.
• Onion: Adds sweetness and depth to the dish, softening as it cooks to blend seamlessly into the sauce.
• Fresh garlic: Gives the curry a bold, savory kick and enhances the overall flavor profile.
• Ginger: Lends a warm, zesty note that brightens the dish and balances the richness of the coconut and peanut butter.
• Thai red curry paste: This is the heart of the curry's flavor, contributing heat, spice, and complexity. I like Thai Kitchen brand. 

For the Slow Cooker

• Vegetable or chicken broth: Acts as the cooking liquid, providing moisture and a savory base for the curry. I recommend using low-sodium versions. 
• Diced tomatoes: Adds acidity and sweetness.
• Fish sauce: A key umami booster that gives the dish a deep, savory flavor typical in Thai cuisine. I recommend the Red Boat brand. 
• Tamari or soy sauce: Adds saltiness and another layer of umami to the curry, enhancing the overall flavor without overpowering it.
• Brown sugar: Balances the heat and acidity with a hint of sweetness.
• Cauliflower: Soaks up the curry sauce, adding texture and heft to the dish.
• Red potatoes: Adds a starchy element that helps thicken the sauce slightly and makes the curry heartier.
• Coconut milk: Provides the creamy, rich base that makes Massaman curry so comforting. It balances the heat from the curry paste and creates a luscious sauce.
• Peanut butter: Gives the curry its signature nutty flavor and thickens the sauce, adding richness and depth.
• Frozen green beans: Introduces brightness and color to the dish.
• Roasted unsalted peanuts: Adds crunch and texture.
• Sriracha: Contributes a touch of heat and a hint of tang. Add more or less depending on your spice preferences.
• Salt and black pepper

For Serving

• Cooked rice or quinoa: A neutral base to soak up the rich, flavorful curry sauce and complete the meal.
• Chopped peanuts: Adds an extra layer of crunch and flavor on top of the curry.
• Chopped cilantro: Brings freshness and a bright, herbal note.
• Sriracha: Optional, but a great way for spice lovers to add extra heat to their bowl!

The Key to Authentic Flavor

Step-by-Step Instructions

Recipe Tips

• You’ll need a 4- to 7-quart slow cooker (I use this 6-quart model, which I recommend) for this recipe. Different slow cookers cook at different rates, so use the times as an approximation. 
• It won’t look like much liquid in the slow cooker at first with the vegetables, but the vegetables will release liquid as they cook (if you add too much liquid at the beginning the dish will be watered down).
• Feel free to swap out the potatoes for cubed butternut squash and/or the green beans for a few handfuls of spinach. I use frozen green beans, which are pre-blanched, meaning they just need a few minutes to warm through in the curry. If you use fresh green beans, blanch them first in boiling water.
• Be sure to use unsalted roasted peanuts in the curry (salted peanuts will be too salty).
• The coconut milk and peanut butter are added at the end, giving the curry a creamy consistency (if added earlier they tend to separate).
• Find a ton of other slow cooker recipes in my book, Fresh Flavors for the Slow Cooker!

Substitutions and Variations

Serving Tips

We love serving this massaman curry recipe over a bed of fluffy jasmine rice (quinoa works, too!). It’s the ultimate one-bowl comfort food. Don’t forget to sprinkle chopped peanuts and cilantro on top for extra texture and freshness. And, of course, add sriracha if you like things spicy—you’ll want to savor every spoonful of that creamy, nutty sauce!

Storage and Make Ahead Tips

Up to 2 days ahead: Cook the aromatics and refrigerate. Chop the cauliflower and potatoes and store them in the fridge (keep potatoes in water to prevent browning; drain before use).

Storage: Leftover curry can be stored in an airtight container and refrigerated for up to 5 days or frozen for up to 3 months. Simply reheat and enjoy!

*This post contains Amazon and other affiliate links to products I use and love (from which I earn income, at no cost to you). Thank you for supporting From Scratch Fast!

Watch the Video!

More Slow Cooker Recipes to Try

• Slow Cooker Carnitas
• Mexican-Inspired White Bean & Chicken Soup
• Curried Red Lentil & Kale Soup
• Slow Cooker Salmon with Creamy Cilantro Sauce
• Easy Vegan Red Lentil Dal

Stay Connected

I'd love to answer any of your questions and see what you're cooking!! Don't forget to give this recipe a star rating and leave a comment below. Follow along on Instagram, Facebook, YouTube & Pinterest, and be sure to tag @nickisizemore so that I can share your creations!

Get the Recipe!

Print Recipe Pin Recipe

Easy Thai-Style Slow Cooker Vegetable Massaman Curry Recipe

Adapted from Fresh Flavors for the Slow Cooker: Reinvent the Slow Cooked Meal (Storey Publishing, 2019), by Nicki Sizemore. Whenever we go out for Thai food my husband orders chicken massaman, a rich coconut-based curry with meat, potatoes and peanuts. This lighter vegetable-packed curry takes inspiration from that dish, using peanut butter and coconut milk to thicken the sauce. It’s now one of James’s favorite weeknight meals—and mine too.

Prep Time30 minutes mins

Cook Time3 hours hrs

Total Time3 hours hrs 30 minutes mins

Course: Main Course

Cuisine: American

Keyword: easy thai vegetable curry, slow cooker vegetable curry recipe, vegetable massaman curry recipe

Servings: 6 people

Author: Nicki Sizemore

Ingredients

Aromatics

• 1 tablespoon virgin coconut oil
• 1 medium onion, finely chopped
• 3 garlic cloves, minced
• 1 tablespoon minced ginger
• 2 tablespoons red curry paste

Slow cooker

• 2 cups low-sodium vegetable or chicken broth
• 1 (14.5 ounce) can diced tomatoes
• 2 tablespoons fish sauce (preferably Red Boat brand)
• 1 tablespoon tamari or soy sauce
• 1 tablespoon packed brown sugar
• 1 large head cauliflower (2 ½ pounds), cut into 2-inch florets
• 1 pound red potatoes (about 3 medium potatoes), cut into 1-inch pieces
• ½ cup canned coconut milk, well stirred
• ½ cup creamy peanut butter
• 2 cups frozen cut green beans
• ⅓ cup roasted, unsalted peanuts
• 1 tablespoon sriracha
• Salt and freshly ground black pepper

For serving

• Cooked rice or quinoa
• Coarsely chopped peanuts
• Chopped cilantro
• Sriracha

Instructions

Start the aromatics

• Heat the coconut oil in a medium skillet over medium-high heat. Add the onion, and season with salt and pepper. Cook, stirring occasionally, until slightly softened, about 3 minutes. Add the garlic, ginger and curry paste, and cook, stirring, until fragrant, 30-60 seconds. Scrape the mixture into a 4- to 7-quart slow cooker. (Alternatively, toss all of the ingredients together in a heatproof bowl and microwave on high, stirring occasionally, until softened, about 4 to 5 minutes.)

Assemble the slow cooker

• Stir in the broth, tomatoes, fish sauce, tamari and brown sugar. Add the cauliflower and potatoes, and toss to coat. Cover and cook until the vegetables are tender, 5 to 6 hours on low or 3 to 4 hours on high.
• Combine the coconut milk and peanut butter in a heatproof bowl and microwave until warm, about 1 minute (alternatively, you can warm them in a small pot on the stove); stir until smooth. Increase the slow cooker heat to high (if it’s not already). Pour the coconut milk mixture into the slow cooker, and add the green beans and peanuts. Cover and cook until warmed through, about 10 minutes. Add the sriracha, and season with salt and pepper.

Serve

• Serve the curry over rice or quinoa, and sprinkle with chopped peanuts and cilantro. Serve with sriracha for drizzling.

Notes

Slow Cooker Jumpstarts:

Up to 2 days ahead:

• Cook the aromatics and refrigerate.
• Chop the cauliflower and potatoes and refrigerate separately (store the potato in water to prevent browning—drain before using).

Storage: The cooked curry can be refrigerated for up to 5 days or frozen for up to 3 months.

Tips:

• You’ll need a 4- to 7-quart slow cooker (I use this 6-quart model, which I recommend) for this recipe. Different slow cookers cook at different rates, so use the times as an approximation. 
• It won’t look like much liquid in the slow cooker at first with the vegetables, but the vegetables will release liquid as they cook (if you add too much liquid at the beginning the dish will be watered down).
• Feel free to swap out the potatoes for cubed butternut squash and/or the green beans for a few handfuls of spinach. I use frozen green beans, which are pre-blanched, meaning they just need a few minutes to warm through in the curry. If you use fresh green beans, blanch them first in boiling water.
• Be sure to use unsalted roasted peanuts in the curry (salted peanuts will be too salty).
• The coconut milk and peanut butter are added at the end, giving the curry a creamy consistency (if added earlier they tend to separate).
• Find a ton of other slow cooker recipes in my book, Fresh Flavors for the Slow Cooker!