Sweet Potato Gratin Recipe

Ingredients

• cooking spray
• 2 cups heavy cream
• 1/2 stick unsalted butter
• 2 cloves garlic, minced
• 1 tablespoon chopped fresh parsley, or more to taste
• 1 tablespoon fresh thyme leaves, or more to taste
• 1 tablespoon minced fresh sage, or more to taste
• 1 tablespoon minced fresh rosemary, or more to taste
• 1 1/2 teaspoons sea salt
• 3/4 teaspoon ground black pepper
• 3 pounds sweet potatoes, peeled and thinly sliced
• 1 1/2 cups shredded Gruyere cheese