Step 1: Prepare the Beef Filling

1. Cook the Beef: In a large skillet over medium heat, add the ground beef. Cook, breaking up the meat with a wooden spoon, for about 5-7 minutes until it’s fully browned. If using ground turkey or a lean meat, you may want to add a tablespoon of olive oil to prevent sticking.
2. Sauté the Onion and Garlic: Add the chopped onion to the skillet with the beef and cook for another 3 minutes, or until the onion becomes translucent. Add the minced garlic and cook for an additional 30 seconds, just until fragrant. Season the mixture with salt, pepper, paprika, and thyme (if using), stirring to incorporate the spices.
3. Drain Excess Fat: If there’s a lot of grease in the skillet, carefully drain any excess fat to prevent the casserole from becoming too oily.

Step 2: Prepare the Creamy Sauce

1. Combine the Soup, Sour Cream, and Milk: In a medium bowl, whisk together the can of cream of mushroom soup, sour cream, and milk until smooth. This will create the creamy base of the casserole that ties all the ingredients together.
2. Add the Cheese: Stir in 1 cup of shredded cheddar cheese (reserving the rest for later) into the soup mixture. This adds a rich, cheesy flavor that complements the tater tots and ground beef perfectly.
3. Add Optional Veggies: If you’re including vegetables like corn, green beans, or bell peppers, add them to the sauce mixture at this stage and stir to combine.

Step 3: Assemble the Casserole

1. Preheat the Oven: Preheat your oven to 375°F (190°C) and lightly grease a 9×13-inch baking dish with cooking spray or a small amount of oil.
2. Layer the Beef Mixture: Spread the cooked beef mixture evenly over the bottom of the prepared baking dish. This layer will provide a savory, flavorful foundation for the casserole.
3. Pour the Creamy Mixture: Pour the soup and cheese mixture over the beef layer, spreading it evenly to cover all the meat. This layer adds creaminess and ensures that every bite is rich and satisfying.
4. Add the Tater Tots: Arrange the frozen tater tots in a single layer over the top of the casserole, making sure they’re evenly distributed. The tater tots will become crispy and golden as they bake, adding a crunchy contrast to the creamy filling.

Step 4: Bake the Casserole

1. Bake: Place the casserole in the preheated oven and bake for 35-40 minutes, or until the tater tots are golden brown and crispy.
2. Add the Remaining Cheese: Remove the casserole from the oven and sprinkle the remaining 1 cup of shredded cheese on top. Return the casserole to the oven and bake for an additional 5-7 minutes, or until the cheese is melted and bubbly.
3. Cool Slightly Before Serving: Let the casserole cool for a few minutes before serving. This helps the layers set and makes it easier to scoop.

Step 5: Garnish and Serve

1. Add Fresh Herbs: Sprinkle fresh chopped parsley or chives over the casserole for a burst of color and flavor.
2. Serve Hot: Serve the casserole hot, scooping generous portions onto plates or bowls. This dish pairs wonderfully with a crisp side salad or steamed vegetables for a balanced meal.