Mushroom-Swiss Hamburger Pie

Ingredients

• 283.5 g baby bella mushrooms
• 1 Tbsp dijon mustard
• 1 tsp dried thyme
• 1 large egg and 1 egg white
• 1 tsp fresh salt and ground pepper
• 680.39 g lean ground beef
• 54 ml olive oil
• 340.19 g dark stout beer
• 1 medium sweet diced onion
• 85.05 g low fat shredded swiss cheese
• 108 g whole wheat fresh bread crumbs