Pepper Crusted Burger - Sutter Home Family Vineyards

Ingredients

• 1 & 1/2 lbs. 15% fat beef burger
• 1/2 c. of whole peppercorns crushed
• 1 & 1/2 tsp. kosher salt
• 6 slices of cheddar cheese
• 3 medium walla walla onions sliced into thin rings
• 1 lb. crimini mushrooms thinly sliced
• 6 pub style buns
• 12 tbsp. mayonaise
• cooking spray
• vegetable oil for grill