Sauté the chicken: Heat olive oil in a large pot or Dutch oven over medium-high heat. Add chicken cubes and cook until browned on all sides. Remove chicken and set aside.
Cook the veggies: Add onion and bell peppers to the pot, cooking until softened, about 5 minutes. Stir in garlic and cook for another minute until fragrant.
Combine ingredients: Return chicken to the pot. Add diced tomatoes (with juice), coconut milk, rice, chicken broth, thyme, cumin, cayenne (if using), salt, and pepper. Bring to a boil.
Simmer to perfection: Reduce heat to low, cover, and simmer for 20–25 minutes, or until rice is tender and liquid is absorbed. Stir occasionally to prevent sticking.
Serve: Garnish with chopped cilantro and serve warm.
Serving and Storage Tips
