Portabello and Bearnaise Burger w/ Garlic & Herb Spread - Sutter Home Family Vineyards

Ingredients

• 2 pounds ground chuck (80% lean)
• 1 shallot, finely chopped
• 2 tablespoons Worcestershire sauce
• coarse salt and pepper (teaspoon of each)
• vegetable oil, for brushing the grill rack
• 1 tablespoon olive oil
• 2 tablespoons balsamic vinegar
• 18 thick cut slices of portabello mushrooms
• 4 tablespoons butter
• 1 packet of Béarnaise Sauce Mix
• ¾ cup whole milk
• 6 soft Kaiser rolls, split
• 3/4 cup Alouette Garlic and Herb Spread
• 6 leaves of green leaf lettuce