Whiskey Burger

Name: Whiskey Burger
Prep time: 1 h
Cook time: 10 min
Total time: 1 h 10 min
Cuisine: American
Ingredients: 4 beef hamburger patties (about a 1 inch thickness, not the thinner patties); 1/4 cup whiskey; 2 tablespoons chopped garlic; 4 strips of bacon, cooked; 8 slices of yellow American cheese; 2 large yellow onions, peeled, cut in half and thinly sliced; 2 tablespoons olive oil; 2 tablespoons butter or reserved bacon grease; 1 teaspoon kosher salt; 4 hamburger buns