French Onion Potato Gratin

Ingredients

• 1 tablespoon butter , plus more for greasing
• 1 tablespoon olive oil
• 2 sweets onions , peeled and cut into thin wedges
• 3 cloves garlic , minced
• 1.25 teaspoons salt
• 0.5 teaspoons ground black pepper
• 1.5 cups whipping cream
• 0.5 cups milk
• 1 tablespoon fresh thyme
• 3 pounds yukon gold potatoes , thinly sliced
• 2.5 cups shredded Gruyere cheese
• 1 cup French fried onions
• 2 cups garlic and herb croutons , coarsely crushed

Instructions

1. 1

   Gather all ingredients.

2. 2

   Lightly grease a 3-quart rectangular or oval baking dish.

3. 3

   Heat butter and olive oil in a large skillet over medium heat. Stir in onion wedges. Cook, covered, until onions are tender, stirring occasionally, about 20 minutes. (If necessary, reduce heat to medium-low to prevent overbrowning before onions are tender.) Increase heat to medium-high and cook, uncovered, until onions are golden, stirring frequently, about 5 minutes more. Add garlic and cook 30 seconds more. Remove from heat and season with 1/4 teaspoon each salt and pepper. Set aside.

4. 4

   Preheat the oven to 350 degrees F (180 degrees C).

5. 5

   Stir together whipping cream, milk, thyme, remaining 1 teaspoon salt, and 1/4 teaspoon pepper; in a bowl; set aside.

6. 6

   Arrange half of the potatoes in the prepared dish, overlapping as necessary. Sprinkle with caramelized onions. Sprinkle with 1 cup Gruyere cheese. Layer remaining potatoes over cheese. Pour cream mixture over potatoes and top with 1 cup Gruyere cheese.

7. 7

   Bake in the preheated oven for 50 minutes.

8. 8

   Top with French friend onions, crushed croutons, and remaining 1/2 cup cheese. Bake until potatoes are tender and cheese is melted, 10 to 15 minutes more. Let stand for 15 minutes before serving.