Savory Burgers with Stroganoff Sauce - Sutter Home Family Vineyards

Ingredients

• 1 pound lean ground beef
• 1/2 cup grated skinned, raw potato
• 1 egg
• 1/4 teaspoon salt
• 1/8 teaspoon black pepper
• 1 tablespoon Worcestershire sauce
• vegetable oil for brushing the grill rack
• 1 (3-oz.) can mushroom stems and pieces, drained
• 1 (12-oz.) jar homestyle beef gravy
• 1/2 cup sour cream
• 6 kaiser rolls, split
• 6 lettuce leaves
• 6 red onion slices