Ingredients
- 1 onion, sliced into thin rings
- 1/2 cup white vinegar
- 1/2 cup all-purpose flour
- Salt and pepper
- 1/4 teaspoon cream of tartar
- 2 pounds 85 percent lean ground beef
- 3 garlic cloves, minced
- 2 teaspoons plus 2 cups vegetable oil
- 4 slices deli American cheese (4 ounces)
- 4 hamburger buns, toasted and buttered
Preparation
Step 1
1. Adjust oven rack to middle position and heat oven to 300 degrees. Separate onion rings and combine with vinegar in bowl. Combine flour, ½ teaspoon salt, ¼ teaspoon pepper, and cream of tartar in large bowl.
2. Gently knead beef, garlic, ¾ teaspoon salt, and ½ teaspoon pepper together in bowl until well combined. Shape beef mixture into four ¾-inch-thick patties and press shallow divot in center of each. Heat 2 teaspoons oil in 12-inch nonstick skillet over high heat until just smoking. Transfer burgers to skillet and cook without moving them for 2 minutes. Flip burgers and cook for 2 minutes on second side. Transfer to rimmed baking sheet, place 1 slice of cheese on each burger, and bake until burgers register 125 degrees (for medium-rare), about 5 minutes.
3. Meanwhile, wipe skillet clean and heat remaining 2 cups oil over medium-high heat to 350 degrees. Drain onion rings and toss in flour mixture until evenly coated. Fry onion rings, stirring occasionally, until golden brown and crisp, about 5 minutes. Transfer to paper towel–lined plate. Place burgers on bun bottoms, add desired condiments, and top with onion rings. Serve.