Artichoke, Leek, and Potato Casserole

Preheat oven to 425 degrees. In a large skillet, heat 1 tablespoon oil over medium-high. Add leeks and celery; cook until softened, 8 minutes. Add artichokes, broth, and cheese and stir to combine. Remove skillet from heat, add lemon juice, and season with salt and pepper. Brush a 1 1/2-quart baking dish with oil. Arrange half the potato slices in a single layer, overlapping slightly; season with salt and pepper. Top with artichoke mixture; smooth top. Layer with remaining potatoes, brush with 2 teaspoons oil, and season with salt and pepper. Bake until sauce is bubbling and potatoes are golden and tender, 35 to 40 minutes. Let cool 10 minutes before serving.