Potato Fennel Gratin

Step 1

Preheat oven to 450°F with rack in lower third of oven. Butter a 2-quart shallow flameproof gratin pan or baking dish (not glass.)

Step 2

Cut fronds from fennel and chop enough to measure 1 tablespoon. Set aside. Cut off and discard stalks. Quarter fennel lengthwise and cut very thinly with slicer into a large bowl.

Step 3

Peel potatoes and cut very thinly with slicer into bowl. Add butter with 3/4 teaspoon salt and 1/4 teaspoon pepper and toss to coat.

Step 4

Transfer vegetables to gratin dish, spreading them out in an even layer, and cover tightly with foil.

Step 5

Bake 30 minutes, then reduce oven to 350°F and continue to bake until vegetables are tender, 20 to 25 minutes more.

Step 6

Remove from oven and remove foil, then sprinkle gratin evenly with cheese.

Step 7

Preheat broiler and broil gratin 4 to 5 inches from heat just until cheese is lightly golden 4 to 5 minutes.

Step 8

Let gratin stand 5 minutes before serving.