Sicilian-Style Potato Gratin

Ingredients

• 3 tablespoons capers drained
• 6 servings coarse kosher salt 
• 1  garlic clove halved
• 2 cups low-salt chicken broth 
• 6 servings olive oil divided for brushing plus 4 tablespoons,
• 2 cups onions chopped
• 8 tablespoons pecorino romano cheese divided packed grated ()
• 2.3 pounds russet potatoes peeled very thinly sliced

Equipment

• frying pan
• oven
• aluminum foil
• glass baking pan

Directions

1. Preheat oven to 350°F. Rub 13x9x2-inch glass baking dish with cut side of garlic clove.
2. Brush dish with olive oil.
3. Heat 2 tablespoons oil in heavy large skillet over medium heat.
4. Add onions, sprinkle with coarse salt, and sauté until soft and beginning to brown, stirring frequently, about 13 minutes.
5. Arrange 1/3 of potatoes in even layer in prepared dish.
6. Sprinkle with coarse salt and pepper. Scatter half of onions over.
7. Sprinkle with 2 tablespoons Pecorino Romano and 1 tablespoon capers. Repeat layering with half of remaining potatoes, coarse salt and pepper, remaining onions, 2 tablespoons Pecorino Romano, and 1 tablespoon capers.
8. Drizzle with 1 tablespoon olive oil.
9. Arrange remaining potato slices over.
10. Sprinkle with coarse salt and pepper and remaining 1 tablespoon capers.
11. Drizzle with remaining 1 tablespoon olive oil.
12. Pour chicken broth over. Press down firmly on potatoes to compact gratin.
13. Cover gratin tightly with foil and bake until potatoes are tender, about 1 hour 20 minutes. Uncover and sprinkle with remaining 4 tablespoons Pecorino Romano.
14. Bake gratin uncovered until cheese is lightly browned, about 15 minutes.
15. Let gratin stand 10 minutes at room temperature before serving.