In a large skillet, heat the oil over medium heat. Add the sausage, then cook and stir it until it's lightly browned. Remove it from the pan.
Add the onion to the same skillet, then cook and stir for three to five minutes or until it's tender. Stir in the beans, tomatoes, corn and sausage, and bring the pan to a boil. Reduce the heat and simmer, uncovered, for five minutes.
Stir in the rice and spinach, and cook for two to three minutes or until everything has heated through and the spinach is wilted. Sprinkle bowls with the cheese and cilantro before serving.
