Baked Cheeseburger Sliders

Bahan-bahan (12 porsi)

• 1 pound lean ground beef
• 1 medium onion, (finely chopped)
• 2 medium garlic cloves, (minced)
• 3 tablespoons ketchup
• ½ tablespoon yellow mustard
• 1 teaspoon Montreal steak seasoning
• 1 teaspoon Worcestershire sauce
• 12 slider buns
• Twelve 1-ounce slices cheddar cheese
• 1 tablespoon extra virgin olive oil
• 1 tablespoon salted butter
• 1½ teaspoons sesame seeds