Heat the oil in a large, heavy bottom pot over medium-high heat. Season the chicken with salt and pepper, add to the pot, and brown in batches on both sides, 4 to 5 minutes per side. Remove the chicken to a plate. To the pot, add half the onions and half the green peppers (reserve remaining half for another use, such as Round 2 Recipe Black Bean and Pork Stew). Cook until softened, about 3 minutes, and then add the garlic and chile powder and season with salt and pepper. Stir in the rice and let it toast for 2 minutes. Add 4 cups water, tomato sauce, and olives and give it a stir. Put the chicken back into the pot. Bring it to a boil, lower the heat, cover, and simmer until the chicken is cooked through and the rice is tender, 30 to 35 minutes. (Reserve 2 cups rice for another use, such as Round 2 Recipe Rice Cakes with Creamy Cilantro Sauce.) Serve garnished with cilantro.