Ingredients

• 1 shallot, minced
• 1 teaspoon olive oil
• 1 pound ground sirloin
• 1 pound ground chuck
• 1 tablespoon salt
• 1 teaspoon freshly ground black pepper
• 2 tablespoons Worcestershire sauce
• 1 tablespoon Dijon mustard
• 2 tablespoons finely chopped fresh sage leaves
• 5 eggs
• 1/4 cup whole milk
• 1 teaspoon salt
• 1/2 teaspoon freshly ground black pepper
• 6 Portuguese muffins, halved
• 4 tablespoons butter
• 6 slices Gruyere cheese
• 6 slices prosciutto
• 3 tablespoons Dijon mustard
• 3 tablespoons mayonnaise

Instructions

1. Watch how to make this recipe.
2. Saute shallot in olive oil over medium-low heat until softened. Set aside to cool.
3. To make patties combine ground sirloin, ground chuck, salt, pepper, Worcestershire sauce, mustard, sage, and sauteed shallot in a large bowl. Mix well until all ingredients are thoroughly combined. Divide mixture into 6 equal portions and form patties (6 ounces each). Grill patties (in grill pan) over medium-high heat for 4 minutes on each side for medium rare.
4. While patties are cooking, prepare buns. Whisk eggs in a bowl with milk, salt, and pepper. Dip Portuguese muffin halves in mixture 1 at a time (place each on a plate after dipping). Heat 1 tablespoon butter in saute pan over medium heat. Place 3 muffin halves into pan and fry, flipping once until both sides are golden brown. Place cooked muffins onto plate and cover with foil. Repeat process using 1 tablespoon butter for every batch of 3 muffin halves until all have been cooked.
5. When patties have been cooked, remove the patties from the grill pan and rest on a half-sheet pan. Top with cheese slices and tent with aluminum foil. Repeat process with the remaining patties.
6. To assemble the burgers, place 1 patty (with cheese) on bottom half of the Portuguese muffin. Top with prosciutto, spread with 1 tablespoon of sauce, and add top of muffin. Serve.