Gather the ingredients. Preheat the oven to 350 degrees F (175 degrees C).

Place sausage in a large, deep skillet. Cook over medium-high heat until evenly brown, about 5 to 7 minutes. Drain, and spread evenly in the bottom of a 9x13-inch pan. Sprinkle cheese over sausage.

Beat milk and eggs together in a large bowl. Pour over cheese. Casserole can be refrigerated overnight at this point if desired. Top with tater tots.

Bake in the preheated oven for 35 to 45 minutes. Cool briefly before serving.