In a large pot or Dutch oven, heat the vegetable oil over medium heat. Add the chopped onion and sauté until softened, about 5 minutes.
Add the minced garlic, ginger, and lemongrass to the pot and sauté for 1-2 minutes, until fragrant.
Add the chicken cubes to the pot and cook until browned on all sides, about 5 minutes.
In a small bowl, mix together the turmeric powder, cumin powder, coriander powder, cinnamon powder, and cayenne pepper. Add the spice mixture to the pot and stir to combine.
Pour in the coconut milk, chicken broth, fish sauce, and brown sugar. Bring the mixture to a boil, then reduce the heat and let simmer for 20-25 minutes, until the chicken is cooked through.
Add the sliced bell peppers and snap peas to the pot and let simmer for an additional 5 minutes, until the vegetables are tender.
Season the curry with salt and pepper to taste, and sprinkle with chopped cilantro before serving.
Notes
Tips and Tricks
Prepare the ingredients ahead of time: Cut the chicken and vegetables and measure out the spices and other ingredients before you start cooking. This will save time and make the cooking process smoother.Use a Dutch oven or large pot: A large pot or Dutch oven will give you enough space to cook the curry and prevent it from boiling over.Toast the spices: Toasting the spices before adding them to the curry will enhance their flavor and aroma.Use low heat: Cook the curry over low heat to ensure that the chicken is cooked through and the flavors are well blended.Adjust the seasoning: Taste the curry before serving and adjust the seasoning if needed. You can add more salt, sugar, or fish sauce to balance the flavors.