Pear-Fennel Gratin with Thyme and Gruyère

Preheat the oven to 375˚F. In a small bowl, combine the cream, sherry (if using), 2 teaspoons of the thyme, the salt, and pepper.

Using a mandoline or chef’s knife, cut the pears lengthwise into thin planks, removing the seeds, core, and stem from the center slices. Slice the fennel bulb lengthwise as thinly as possible.

In a 2-quart baking dish, layer half of the pear planks and half of the fennel slices. Drizzle with half of the cream mixture and sprinkle with half of the cheese. Repeat to create another layer. Cover with foil and bake until the pears and fennel are tender when pierced with a fork, about 1 hour.

Meanwhile, in a small bowl, mix the panko with the remaining 2 teaspoons of thyme, 1 tablespoon coarsely chopped fennel fronds, the olive oil, a pinch of salt, and several grinds of pepper.

Sprinkle the topping over the gratin. Continue baking until the topping is evenly browned and the pears and fennel are very tender, 20 to 25 minutes. Let rest for 5 to 10 minutes, then serve hot.