In a 3- or 4-quart saucepan with a lid, heat the olive oil over medium heat.
Add the onion and bell pepper, cook, stirring occasionally, until tender, about 4-6 minutes.
Add the garlic, corn and black beans, oregano, spices and cook until heated through, about 2-3 minutes.
Add the can of diced tomatoes, stock, and rice, stir to combine. Bring to a boil, cover, reduce the heat and simmer until the rice is cooked, about 20 minutes.
Stir in the cheese. Let rest 5 minutes before serving.
Serve garnished with the chopped cilantro.