Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a large mixing bowl, combine the ground beef, finely chopped onion, minced garlic, breadcrumbs, 1/2 cup of ketchup, Worcestershire sauce, beaten egg, dried oregano, salt, and black pepper.
Step 3: Using your hands or a spatula, mix the ingredients until just combined. Be careful not to overmix.
Step 4: Lightly grease the muffin tin with olive oil to prevent sticking.
Step 5: Scoop the meat mixture into each muffin cup, filling them about three-quarters full.
Step 6: Spoon a bit of the remaining ketchup on top of each muffin.
Step 7: Place the muffin tin in the preheated oven and bake for 25-30 minutes, or until the muffins are cooked through.
Step 8: Once baked, remove the muffin tin from the oven and let the muffins cool for a few minutes before serving.