Duxelle Burger

• 1 tbsp. butter
• 1 shallot
• 1 clove garlic
• ½ lb. mixed mushrooms (shiitake, crimini, porcini)
• pinch dried thyme
• salt and pepper, to taste

• ¼ cup mayonnaise
• 1 ½ tsp. Dijon
• 1 small shallot
• 3 gherkins
• 1 lb. medium ground beef
• salt and pepper
• 4 hamburger buns
• 1 cup finely grated Comté cheese
• 1 cup arugula

• For the duxelle, pulse the shallots and garlic in a food processor until finely minced. Heat butter in a large skillet over medium heat. Add the shallots and garlic; cook 3 minutes until soft. Pulse the mushrooms in the food processor until finely chopped. Add the mushrooms to the skillet with a pinch of salt and thyme. Cook, stirring frequently, until the mushrooms have released their liquid, about 15 minutes. Season to taste with salt and pepper.
• For the burger sauce, add the ingredients to a food processor. Process until well combined. Refrigerate until use.
• Divide ground beef into four portions. Season with a pinch of salt and pepper. Form each into a ball then flatten into a patty. Season well all over with salt and pepper. Heat oil in a heavy cast iron skillet over medium high heat. Cook 2 burgers at a time until well browned, about 3-5 minutes. Flip and cook another 3-5 minutes. depending on desired doneness. Repeat with remaining burgers. Top with cheese, cover and let steam until cheese is melted. If desired, toast buns.
• To serve, top bottom bun with duxelle, a burger, and arugula. Spread burger sauce on top bun and enjoy!