Preheat your oven to 375 degrees F. Lightly coat a 9×13-inch baking dish with nonstick spray. Slice the bell peppers in half from top to bottom. Remove the seeds and membranes, then arrange cut side up in the prepared baking dish.
Heat the olive oil in a large, nonstick skillet over medium high heat. Add the beef, chili powder, cumin, garlic powder, salt, and pepper. Cook, breaking apart the meat, until the chicken is browned and cooked through, about 4 minutes. Drain off any excess liquid, then pour in the can of diced tomatoes and their juices. Let simmer for 1 minute.
Remove the pan from the heat. Stir in the rice and ¾ cup of the shredded cheese. Mound the filling inside of the peppers, then top with the remaining cheese.
Pour a bit of water into the pan with the peppers—just enough to barely cover the bottom of the pan. Bake uncovered for 25 to 35 minutes, until the peppers are tender and the cheese is melted. Top with any of your favorite fixings, and enjoy hot.