Bring 1 ¾ cups water to a boil in a saucepan. Add rice, stir, and reduce heat to low. Cover pan and simmer until rice is tender, about 30 minutes.
Place the olive oil, chopped onion, and garlic to a large skilled. Cook over medium heat until softened, about 5 minutes.
Add the pinto beans, black beans with their juice and tomatoes with their juice. Add garlic to skillet. Add corn, chili powder, cumin, and stir to combine. Reduce heat to medium low and simmer until heated through, about 2 minutes.
To serve, put rice in bowls, and top with beans. Add guacamole, cheese, salsa, dairy free cheese, tortilla chips, or other toppings of your choice.
Notes
Store leftovers in the fridge in an airtight container. They should stay fresh for about for 4 days.