Preheat your oven to 375°F and generously spray a 24-cup mini muffin tin with cooking spray. Separate each biscuit and gently press them into the muffin cups, creating small wells. The dough should come about halfway up the sides, forming perfect little edible bowls.

Heat vegetable oil in a large skillet over medium-high heat. Add the diced onion and cook for 3-4 minutes until it becomes translucent and fragrant. Add minced garlic and cook for another 30 seconds until aromatic.

Crumble in the ground beef, breaking it into small, uniform pieces. Cook for 6-8 minutes, stirring frequently, until the meat is beautifully browned and no pink remains.

Drain any excess fat from the pan, leaving just enough to keep the mixture moist. Stir in ketchup, mustard, and Worcestershire sauce, allowing these flavors to meld for about 2 minutes. Season with salt and pepper to taste.

Spoon approximately 1 tablespoon of the beef mixture into each biscuit cup, filling them about three-quarters full. Top each cup with a generous pinch of both cheddar and mozzarella cheeses.

Bake for 12-15 minutes until golden-brown biscuit edges and bubbling, melted cheese on top. The biscuits should sound hollow when gently tapped.

Allow the cups to cool in the pan for 5 minutes before removing. Run a knife around the edges if needed, then gently lift out each cup.