French Onion Soup Sliders with Raclette - Emmi USA

Ingredients

• 2 tablespoons butter
• 1 medium yellow onion, halved and sliced
• Balsamic vinegar
• Salt and pepper to taste
• 1 pound ground beef
• 1/3 cup dry breadcrumbs
• 1 egg
• 1 packet (2 ounces) onion soup mix
• 1 tablespoon Worcestershire sauce
• 1 tablespoon tomato paste
• 8 split slider buns
• 1 tablespoon melted butter
• Sesame seeds, minced garlic and/or poppy seeds, for topping buns, optional
• Dijon mustard
• Arugula
• 16 ounces Emmi Raclette Cheese , divided