– 1 pound lean ground beef – 1/2 teaspoon salt – 2 teaspoons ground black pepper – 2 teaspoons garlic powder – 1/2 white onion, diced – 6 slices cheddar cheese – 9 slider buns – 2 tablespoons unsalted butter, melted – 1 tablespoon roasted white sesame seeds – Lettuce, for topping – Cherry tomatoes, sliced, for topping