Caramelized Onion and Mushroom Crostini

Ingredients (10)

• 5 tablespoons Vermont Creamery Cultured Butter Unsalted , divided
• 1 medium yellow onion , thinly sliced
• 8 ounces shiitake mushrooms cleaned, stemmed and sliced
• 8 ounces brown mushrooms cleaned, stemmed and sliced
• 1 clove garlic , pressed or minced
• 1/4 cup Marsala wine
• 2 teaspoons fresh thyme leaves
• 1/2 teaspoon kosher salt
• 1/4 teaspoon freshly ground black pepper
• 1 loaf baguette