For the Caramelized Onions

• 2 tablespoons unsalted butter
• 1 tablespoon olive oil
• 3 large yellow onions, thinly sliced
• ½ teaspoon kosher salt
• 1 teaspoon brown sugar
• 2 tablespoons beef broth

For the Homemade Garlic Aioli

• 1 large egg yolk, room temperature
• 1 teaspoon Dijon mustard
• 1 garlic clove, finely grated or minced
• 1 tablespoon fresh lemon juice
• ½ cup light olive oil or neutral oil
• Kosher salt, to taste

For the Au Jus Sauce

• ¼ cup unsalted butter
• 1 tablespoon Better than Bouillon Beef Base
• 2 cups beef broth
• 2 teaspoons Worcestershire sauce

For the Roast Beef Sliders

• 12 slider buns, sliced in half (Hawaiian rolls preferred)
• ¼ cup homemade garlic aioli or mayonnaise
• ½ pound deli roast beef, thinly sliced
• 12 slices melty cheese (provolone, Swiss, or muenster)
• ½ cup shredded mozzarella cheese
• 2 cups caramelized onions

For the Garlic Butter Sauce

• 6 tablespoons unsalted butter, melted
• 1 teaspoon Worcestershire sauce
• 1 tablespoon poppy seeds
• 1 tablespoon white sesame seeds
• ½ tablespoon garlic powder
• ½ tablespoon dried minced onion
• ½ teaspoon kosher salt
• Freshly cracked black pepper to taste