My Mexican neighbor brought this over, and it was an instant hit!

1 lb ground beef
1 small onion, diced
1 packet taco seasoning
1 can black beans, rinsed and drained
1 can corn, drained
1 can Rotel tomatoes with green chilies, undrained
2 cups Mexican blend cheese, shredded
1 bag frozen tater tots
1/4 cup sliced black olives (optional)
1/4 cup chopped green onions (optional)
Sour cream and chopped cilantro for garnish (optional)