Ingredients

• 1 tablespoon salt
• 1 teaspoon sugar
• 1/4 cup red wine vinegar
• 1/4 cup water
• 2 shakes hot sauce (recommended: Tabasco)
• 1/2 small red onion, sliced thin (preferably on mandolin)
• 12 ounces ground beef
• 1/4 cup ham, cut into 1/4-inch dice
• 1/4 cup grated Parmigiano-Reggiano
• 1/4 cup Gruyere, cut into 1/4-inch dice
• 1 large clove garlic, smashed and finely chopped
• Kosher salt
• 2 slices Gruyere
• 2 sesame seed buns
• 1/2 cup mayonnaise mixed with 1/2 teaspoon garlic powder
• 2 slices beefsteak tomato
• 1 cup baby arugula, washed

Instructions

1. For the pickled onions: Combine the salt, sugar, vinegar, water, and hot sauce in a container with a lid. Shake to incorporate everything really well. Add the onions and let sit for at least 30 minutes.
2. For the burger: Preheat the grill. Combine all the burger ingredients and season well with salt. Form into 2 equal patties. Grill each burger for about 4 minutes on each side. During the last 2 minutes of grill time, top each burger with a slice of cheese.
3. Open the buns and place the inside on the grill, and grill until the bun is lightly toasted, about 1 minute.
4. To assemble: Schmear the inside of each toasted bun with the garlic mayo. Place the burger patty on the bottom bun. Top each burger with a few pickled onions, a tomato slice, and some arugula. Top with the top half of the bun.