Preheat a grill to medium-high heat.
Mix together the ingredients for the burgers in a large bowl. Shape the mixture into 4 equal patties.
1½ pounds 90% lean ground beef, 1½ teaspoons Worcestershire sauce, 1½ teaspoons McCormick Grill Mates Montreal Steak Seasoning, 1 clove garlic
Cook the burger patties until they’re done to your preference, about 7-9 minutes per side, flipping once.
When they’re almost done, put 1 slice of cheese on each burger, cover the grill, and let the cheese melt.
4 slices Swiss cheese
If desired, split the buns in half and toast them (cut side down) on the grill for a couple minutes.
4 hamburger buns
To serve, put each burger on a bun and top each with 2 tablespoons caramelized onions (see note).
½ cup caramelized onions