Sweet Potato and Leek Gratin with Gruyère Cheese - Chopped

Ingredients

• 2 large sweet potatoes peeled and thinly sliced
• 2 large leeks white and light green parts only thinly sliced
• 2 cups gruyère cheese shredded
• 1 cup heavy cream
• 2 cloves garlic minced
• 2 tablespoons butter
• 1 teaspoon fresh thyme leaves
• 1/2 teaspoon salt
• 1/4 black pepper