Preheat oven to 400°F. Grease a 9-inch pie plate (or a deep 8-inch square baking dish) with nonstick cooking spray; set aside.
In a large skillet, brown ground beef and onion over medium heat until beef is no longer pink (about 8-10 minutes). Drain off fat.
Stir in salt, Worcestershire sauce, ketchup, and cheese. Transfer beef mixture to the prepared pie dish.
In a separate bowl, whisk together Bisquick, milk, and eggs, just until combined (it’s fine if you still have some lumps in the batter – do not overmix).
Pour batter on top of beef.
Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
