Potato Gratin is a traditional French dish, which is often laden down with cheese and heavy cream. This makes it both on the unhealthy side, and unsuitable for serving alongside meat dishes in a kosher home.
But since I love the thinly sliced potatoes and the fun presentation, I made a lighter, pareve version of this classic. Plus, alternating layers of potatoes and sweet potatoes make it more colorful and tasty.
The most important part of this recipe is the slicing of the potatoes – you don’t want them too thin or too thick. They should be just bordering on transparent, but still able to hold their shape. While someone with exceptional knife skills could pull this off by hand, the rest of us need a food processor, fitted with a slicing blade, at medium speed.
Sweet Potato and Potato Gratin
2 large onions
1-2 tablespoons oil
2 pounds potatoes
2 pounds sweet potatoes
1 ½ cups vegetable or chicken stock or broth, heated
3 tablespoons flour
3 tablespoons oil
1 teaspoon salt
¼ teaspoon black pepper
Peel and slice the onions in to rings. Heat the oil in a large skillet over medium heat. Add the onions and cook, stirring regularly, until brown, 10 to 15 minutes.
Peel the potatoes and sweet potatoes. Slice them in to approximately 1/8” slices.
Mix together the warm broth, flour, oil, salt and pepper, and stir until smooth.
Lightly spray or oil the bottom of a glass baking dish (about 9×13”). Beginning with the potatoes, alternate layers of potato, sweet potato and onion. After half of the ingredients have been placed, pour half the broth mixture over the top, then continue layering until all the ingredients have been used up. Top with the remaining broth mixture.
Bake on 375 F for about 1 ½ hours.