Fontina Cheeseburgers with Lemon-Herb Mayonnaise | Red Meat Recipes | Weber Grills

Ingredients

• 1 cup/240 milliliters mayonnaise
• 2 tablespoons finely chopped fresh chives
• 1½ tablespoon finely chopped fresh Italian parsley leaves
• 2 teaspoons finely chopped fresh thyme leaves
• 2 garlic cloves, minced
• 1 teaspoon freshly grated lemon zest
• 1 teaspoon fresh lemon juice
• 1½ pound/680 grams ground chuck (80% lean)
• 1 teaspoon kosher salt
• ¼ teaspoon freshly ground black pepper
• 1 large yellow onion, cut crosswise into four slices about ½ inch thick
• 2 tablespoons extra-virgin olive oil, divided
• 5 ounces/140 grams Fontina cheese, thinly sliced
• 4 Hawaiian sweet sandwich buns, or other soft sandwich buns, split
• 4 large leaves butter lettuce