Cook rice according to the package directions. When the rice is done, fluff with a fork and season with salt and pepper to taste. Cover with a lid to keep warm.
In the meantime, heat the oil in a saucepan over medium heat. Sauté the garlic, onion, and cumin for 3-4 minutes. Add in the black beans, and season with salt and pepper. Fill the can a quarter of the way with water and slosh it around to get any remaining juices, then add it to the saucepan. Simmer for 15-20 minutes. Take off the heat and stir in half of the cilantro. Season with salt and pepper to taste.
Mix the lime juice and remaining cilantro into the rice. Serve with beans.