Ingredients:

  • 2 tablespoons olive oil (30 ml)
  • 4 large yellow onions, thinly sliced (about 800g)
  • 1 teaspoon sugar (5 g)
  • 1/2 teaspoon salt (3 g)
  • 1/4 teaspoon black pepper (1 g)
  • 1/4 cup dry red wine (such as Cabernet Sauvignon or Merlot) (60 ml)
  • 1/4 cup beef broth (60 ml)
  • 1 tablespoon balsamic vinegar (15 ml)
  • 1 tablespoon olive oil (15 ml)
  • 1 pound (450g) ground beef (80/20 blend recommended)
  • 1 teaspoon garlic powder (5g)
  • 1/2 teaspoon onion powder (3g)
  • 1/2 teaspoon dried thyme (3 g)
  • Salt and pepper to taste
  • 12 slider buns, split (Hawaiian rolls work great!)
  • 6 ounces (170g) Gruyère cheese, shredded (or Swiss, provolone, or mozzarella)
  • 2 tablespoons melted butter (30 ml), for brushing the buns (optional)
  • Chopped fresh parsley, for garnish (optional)

Instructions:

  1. Heat olive oil in a large skillet. Add onions, sugar, salt, and pepper. Cook over medium-low heat, stirring occasionally, until deeply golden brown and caramelized (about 45 minutes - this is key!). Deglaze with red wine and beef broth, scraping up any browned bits. Simmer until liquid is almost evaporated, then stir in balsamic vinegar. Set aside.
  2. Heat olive oil in a separate skillet. Add ground beef and cook, breaking it up with a spoon, until browned. Drain any excess grease. Season with garlic powder, onion powder, thyme, salt, and pepper.
  3. Preheat oven to 350°F (175°C). In a bowl, mix the caramelized onions with the ground beef.
  4. Arrange slider bun bottoms in a baking sheet. Top each bun with the beef and onion mixture. Sprinkle generously with shredded Gruyère cheese.
  5. Place the slider bun tops over the cheese. Brush the tops with melted butter (optional). Bake for 10-12 minutes, or until the cheese is melted and bubbly and the buns are lightly golden.
  6. Sprinkle with chopped parsley (optional) and serve immediately.