You can use any veggies you like in this easy, flavorful weeknight curry!
Heat the oil in a large skillet over medium heat. Season the chicken with salt. Working in two batches, brown the chicken on all sides, about 5 minutes total. Transfer the chicken to a plate.
Add the onion, bell pepper, and mushrooms to the skillet. Cook, stirring, until the vegetables have softened and the onion is translucent, about 5 minutes. Add the garlic and ginger and cook for 30 seconds. Add the curry powder, sugar, and red pepper flakes (if using), and stir to combine.
Stir in the coconut milk and chicken stock. Return the chicken and any juices to the skillet. Simmer until the chicken is cooked through, about 5 minutes. Stir in the snow peas and spinach and cook until the snow peas are bright green and the spinach has wilted, 2 to 3 minutes. Remove from the heat and stir in the lime juice.
Serve over rice.