Cook rice according to package directions, omitting salt and fat.
Remove casings from sausage. Cook sausage in a large skillet over medium-high heat until browned, stirring to crumble. Remove from the pan with a slotted spoon.
Add corn and garlic to pan, and cook over medium heat 3 minutes, stirring frequently. Stir in rice, sausage, cheese, chili powder, cumin, pepper, and salt. Reduce heat to low, and cook, stirring constantly, until thoroughly heated. Sprinkle with cilantro, if desired.