Mini Burgers with Caramelized Onions

📸: Francesco Lagnese

By Martha Stewart

Ingredients

For the Caramelized Onions

• 2 tablespoons extra-virgin olive oil
• 3 medium onions, thinly sliced
• 1/4 cup red wine
• 4 sprigs thyme
• Coarse salt and freshly ground pepper

For the Burgers

• 2 tablespoons extra-virgin olive oil
• 1 small onion, preferably Vidalia, finely chopped
• 1 pound ground beef
• 1 tablespoon chopped fresh flat-leaf parsley
• Coarse salt and freshly ground pepper
• 1.5 oz. Comte cheese, thinly sliced, cut into 1 1/2-inch squares
• 3 red tomatoes, such as Campari, sliced 1/4-inch thick
• 8 three-inch mini brioche buns, split in half

Directions

1. Make the onions: Heat oil in a medium skillet over medium-high heat. Add onions and cook, stirring occasionally, until soft, about 8 minutes. Reduce heat to medium-low and continue cooking, stirring occasionally, until nicely browned and caramelized, about 30 minutes more.
2. Add wine, thyme, and 1/4 cup water. Raise heat to medium-high and cook, stirring occasionally, until the liquid has evaporated, about 3 minutes. Season with salt and pepper.
3. Make the burgers: heat oil in a small skillet over medium-high heat. Add onion and cook, stirring occasionally, until translucent, about 2 minutes. Remove from heat and let cool completely.
4. Heat a grill to medium-high. Combine beef, parsley, and onion in a bowl. Season with salt and pepper. Form into 8 one-inch-thick patties. Grill 4 to 5 minutes per side for medium-rare. Top with a square of cheese after flipping burger if desired. Assemble with caramelized onions and skewers.