Tamari Umami Burgers - San-J

Ingredients

• 1 tablespoon unsalted butter
• 1 tablespoon olive oil
• 4 cups thinly sliced onions
• 1 pound lean ground beef
• 1 1/2 teaspoons San-J Tamari Lite 50% Less Sodium Gluten Free Soy Sauce
• 2 cloves garlic (finely grated)
• 1 teaspoon black pepper
• 1/2 teaspoon sugar
• 4 lettuce leaves