Cook the Meat: In a skillet over medium heat, add olive oil and sauté chopped onion until softened. Add the ground beef or sausage and cook until browned. Drain excess fat. Stir in taco seasoning and a splash of water, then let simmer for 2 minutes.
Prepare the Shells: Warm taco shells according to package instructions (or toast lightly in the oven for extra crispness).
Assemble the Tacos: Spread a spoonful of pizza sauce inside each taco shell. Fill with seasoned beef mixture, then sprinkle generously with mozzarella cheese.
Add Pepperoni: Tuck in 2–3 pepperoni slices per taco, on top of the cheese.
Melt and Serve: Place the tacos on a baking sheet and broil for 2–3 minutes, just until the cheese melts and gets bubbly.
Finish: Garnish with fresh basil or parsley if desired, and serve warm.
