Potato Gratin with Leeks and Thyme

INGREDIENTS

• 2 Tbs. olive oil
• 2 leeks, about 8 oz. total, halved lengthwise, white and light
• green portions thinly sliced
• 1 tsp. chopped fresh thyme
• 1 1/2 tsp. kosher salt
• 1/4 tsp. freshly ground pepper
• 1 1/2 lb. red potatoes, each about 2 inches in diameter, cut into
• 1/8-inch-thick rounds
• 1 1/2 cups chicken broth