Heat oven to 425° F.and spray a 9 x 13 inch pan with non-stick cooking spray.
In a large pan, brown the ground meat over medium heat until thoroughly cooked. Crumble the meat as you cook it so it is in small pieces when it's done. Do not drain the meat.
Add the garlic, salt, pepper, paprika, onion powder, thyme, and mustard. Stir to completely combine.
Stir in the butter and Worcestershire sauce. Continue to cook over medium heat. Stir to melt the butter completely.
Sprinkle the flour over the meat and stir in. Cook for 1 minute over medium heat.
Stir in the milk slowly and bring back to a very low simmer over medium heat. Simmer for 1 minute.
Stir in half the cheese. Blend until melted.
Pour the meat mixture into the prepared casserole pan, and sprinkle the remaining cheese over the top. Arrange the tater tots over the top of the cheese.
Bake at 425 degrees for 21 - 25 minutes until mixture is bubbly and tater tots are light golden brown.