Preheat oven to 425 F. Line baking sheet with foil.
For the rice: In pot bring 1 cup of water to boil. Once at rolling boil add in 1/2 cup rice. Cover and simmer for about 20 minutes or until thoroughly cooked. Once cooked, set aside.
Rinse and drain beans.
Chop and dice onion, zucchini, and carrots.
For the bell peppers: Cut tops off the bell peppers. Carefully remove the seeds and membrane. Optional: I like to chop and dice the tops and add it to the vegetable & bean mix to tie in the flavors. Tops can also be saved and used during the baking process. Add olive oil to a pan. Once olive oil is heated, add in onion, zucchini, and carrot. Sauté vegetables until onions are translucent and carrots and zucchini is soft.
Add black beans to the pan and toss in salt and spices. Continue to sauté until thoroughly mixed. Optional: This is where you could add in the diced bell pepper tops unless saving the tops for baking. Add cooked brown rice to the vegetable and bean mix. Combine thoroughly and set aside.
Scoop vegetable and bean mix into the bell pepper cups until filled completely.Optional: Sprinkle cheese on top Bake for 20 minutes. Once cooked, let cool for 5 minutes before serving. Optional: Sprinkle cilantro on top.