With Horseradish & a Dijon Crust

Serves 8

For the Topping:
1 ½ C Coarse Fresh Breadcrumbs (from an airy, crusty loaf like Ciabatta)
2 Tbsp unsalted Butter, melted
Kosher Salt
1 Tbsp Dijon Mustard
2 Tbsp grated Parmigiano Reggiano
2 tsp chopped fresh parsley

For the Gratin:
2 Tbsp unsalted Butter, plus ½ tsp for the dish
1 C thinly sliced shallots (6 to 7 large)
Kosher Salt
2/3 C Heavy Cream
2/3 C homemade or low-salt canned Chicken Broth
2 Tbsp prepared Horseradish
Freshly ground Black Pepper
2 Yukon Gold Potatoes (approx ¾ lb)
1 Sweet Potato (approx ¾ lb)
1/3 C grated Parmigiano Reggiano

Topping Preparation:
Combine the breadcrumbs, melted butter, and a pinch of salt in a bowl. Mix in the mustard and then the Parmigiano and parsley.

Prepare the Gratin:
Heat the oven to 350 degrees. Rub a shallow 2 qt gratin dish with ½ tsp of the butter. Melt the 2 Tbsp butter in a small saucepan over medium heat. Add the shallots and a big pinch of salt; cook, stirring frequently, until softened, limp, and somewhat golden. Whisk together the cream, broth, and horseradish; add to the shallots. Season with salt and pepper, stir to combine, and remove from heat.

Assemble and bake the Gratin:
Peel the potato and sweet potato, cut each in half lengthwise, and slice each across into thin half moons. In a large bowl, combine the potato slices, 2 tsp salt, the Parmigiano, and the shallot cream. With a rubber spatula, mix gently but thoroughly and scrape into the prepared gratin dish, smoothing and pressing until evenly distributed. Cover with the breadcrumb topping. Bake until the crust is deep golden brown, the juices around the edges have subsided, and the potatoes are tender when pierced with a fork, about 1 hour. Let rest for 15 to 20 minutes before serving.

Gustav Mauler
Certified Master Chef