Step 1: Heat the olive oil in a large skillet over medium-high heat. Add the chopped onion and cook until it becomes translucent, about 3-4 minutes. Then, add the chicken pieces and cook until browned on all sides, approximately 5-7 minutes.
Step 2: Once the chicken is cooked, add the diced jalapeños, red bell pepper, chili powder, garlic powder, cumin, oregano, salt, and black pepper. Stir everything together and cook for another 2-3 minutes until the vegetables soften and the spices become fragrant.
Step 3: Add the rinsed black beans, brown rice, and diced tomatoes with their juices to the skillet. Stir to combine all the ingredients well.
Step 4: Pour in 2 cups of water (or chicken broth for extra flavor) and bring the mixture to a boil. Once boiling, reduce the heat to low, cover the skillet, and let it simmer for about 45 minutes or until the rice is tender and has absorbed the liquid.
Step 5: Once the cooking time is up, remove the skillet from heat. Fluff the rice with a fork and stir in the chopped green onions. Taste and adjust seasoning if necessary.
Step 6: Serve your Mexican Chicken and Rice with optional toppings like fresh cilantro, lime wedges, sliced jalapeños, shredded cheese, diced avocado, salsa, or a dollop of sour cream or Greek yogurt for a creamy finish.