Prepare mashed potatoes according to package directions; keep warm.
Cook beef in a large nonstick skillet over medium-high heat until browned, stirring to crumble. Stir in picante sauce, water, cumin, sugar, salt, and beans; bring to a boil. Reduce heat; simmer until mixture thickens (about 5 minutes).
Remove from heat. Spoon mashed potatoes over meat mixture, and sprinkle with cheese. Cover and let stand 2 minutes or until cheese melts.
Prepared mashed potatoes are found in the refrigerated section of larger grocers. They only need a few minutes in the microwave to reheat.