Smashburgers with Onion

Ingredients

• 2 pounds Ground Beef (93% lean or leaner)
• 4 tablespoons butter
• 1 cup thinly sliced shallots
• 3 cloves garlic, minced
• 1 tablespoon finely chopped fresh thyme
• 8 slices American cheese
• 1/2 cup Japanese-style mayonnaise
• 1 teaspoon granulated onion
• 1 teaspoon garlic powder
• 4 hamburger buns, split, toasted
• 1 cup shredded lettuce
• Pickled Vegetables (optional)