Start by cutting the chicken into bite-sized pieces. Season with salt, black pepper, cumin, paprika, and cayenne pepper (if using).
Heat the olive oil in a large pot or Dutch oven over medium heat. Add the diced onion and sauté for about 3-4 minutes, until it becomes translucent.
Stir in the minced garlic and diced bell pepper; cook for an additional 2-3 minutes until the vegetables are tender.
Add the seasoned chicken to the pot, cooking for about 5-7 minutes until it's browned on all sides.
Pour in the drained diced tomatoes and chicken broth, then bring the mixture to a boil.
Once boiling, stir in the rice, and reduce the heat to low. Cover the pot and let it simmer for 20 minutes, or until the rice has absorbed the liquid and is tender.
In the last few minutes of cooking, stir in the frozen peas, cover again, and allow them to heat through.
Remove the pot from heat, and let it sit covered for 5 minutes. Fluff the rice with a fork before serving.
Serve hot, garnished with fresh cilantro if desired.