Preheat oven to 350 degrees F. Spray a 9x13-inch baking dish with nonstick cooking spray; set aside.

Add ground beef and onion to a large skillet over medium-high heat and cook for 8-10 minutes, breaking up meat, until cooked through.

Add garlic powder, salt, pepper and Worcestershire sauce and stir to combine. Sprinkle flour on top of ground beef and cook, stirring continuously, for 1-2 minutes. Pour beef broth in the skillet and cook for a few minutes until thickened. Add yogurt and mix until well combined.

Fold in green beans and corn then spread mixture into prepared baking dish. Top with frozen tater tots and sprinkle cheese on top.

Bake, uncovered, for 50 minutes, or until tater tots are golden brown and cheese is melted.