Begin by peeling and cutting the potatoes into half-inch cubes. In a mixing bowl, toss the cubed potatoes with curry powder, salt, and pepper until evenly coated.

Preheat your oven to 425°F (220°C). Spread the seasoned potatoes in a single layer on a parchment-lined baking sheet. Roast them for about 20 minutes, tossing halfway through.

In a large pot, heat a splash of oil or vegetable broth over medium heat. Add the minced garlic and mixed vegetables, sautéing for about 5 minutes until they become fragrant.

Once the vegetables are softened, stir in the coconut milk and Massaman curry paste. If using peanut butter, add it now too. Let the mixture come to a gentle simmer, cooking for about 15 minutes.

After simmering, taste your curry and adjust the seasoning with salt and pepper as needed. Ladle portions of the creamy Massaman curry into bowls, and top each serving with the roasted potatoes.