Scalloped Potatoes and Mushrooms 8.000

Deb Lindsey for The Washington Post

Weeknight Vegetarian Dec 18, 2017

This homey dish gets much of its flavor from mushroom broth, making it lighter than versions of scalloped potatoes made with butter and cream. The top crust of Gruyere cheese is a must.

Serve with a green salad and some beans, tofu or other protein of your choice.

To read the accompanying story, see: This cheesy potato casserole can take you home.


Servings:
8

When you scale a recipe, keep in mind that cooking times and temperatures, pan sizes and seasonings may be affected, so adjust accordingly. Also, amounts listed in the directions will not reflect the changes made to ingredient amounts.

Tested size: 8 servings

Ingredients
  • 1 tablespoon olive oil, plus more for the baking dish
  • 1 large yellow or white onion, thinly sliced (about 2 cups)
  • 1 red bell pepper, seeded and finely chopped (about 1 1/2 cups)
  • 1 pound button or cremini mushrooms, trimmed and sliced (heaping 4 cups)
  • 1/4 teaspoon dried thyme
  • 1 1/2 teaspoons kosher salt
  • 1/2 teaspoon freshly ground black pepper
  • 3 pounds Yukon Gold or russet potatoes, peeled and each cut in half lengthwise
  • 2 tablespoons flour
  • 1 1/2 cups grated Gruyère cheese (about 6 ounces)
  • 1 1/2 cups store-bought mushroom broth (see NOTE)

Directions

Preheat the oven to 400 degrees. Lightly grease a 9-by-13-inch baking dish with a little oil (or coat it with cooking oil spray).

Heat the tablespoon of oil in a large pot over medium-high heat. Once the oil shimmers, stir in the onion and red bell pepper; cook, stirring frequently, until the onion starts to become translucent, 5 to 6 minutes. Stir in the trimmed mushrooms, thyme, salt and black pepper; cook until the mushrooms have browned and cooked down a bit, 2 to 3 minutes. Turn off the heat.

Cut the potato halves crosswise as thinly as you can (into half moons, no thicker than 1/4 inch). The yield should be about 6 cups. Layer half the sliced potatoes in the baking dish and then sprinkle evenly with 1 tablespoon of the flour. Spread the mushroom-bell pepper mixture over the potatoes, then scatter one-third of the grated Gruyere over that layer. Use the remaining potato slices to build the next layer, then sprinkle with the remaining tablespoon of flour. Pour the mushroom broth over everything and top with the rest of the cheese.

Cover tightly with aluminum foil; bake (middle rack) for 30 minutes, then uncover and bake until the potatoes are tender and the top is crusty and golden brown, another 30 minutes. Let stand for at least 10 minutes before serving.

NOTE: If you can't find commercially prepared mushroom broth (typically in aseptic quart boxes), pour 2 1/2 cups boiling water over 1/2 cup dried sliced mushrooms, such as shiitake, and let them soak for at least 20 minutes. Strain through a fine-mesh sieve into a large liquid measuring cup. (You'll have more than you need for this recipe, but it can be refrigerated for up to 2 weeks or frozen for up to 3 months.) The soaked dried mushrooms can be rinsed, sliced and added to the fresh mushrooms in this dish.

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Recipe Source

Adapted from "The Moosewood Restaurant Table: 250 Brand-New Recipes from the Natural Foods Restaurant That Revolutionized Eating in America," by The Moosewood Collective (St. Martin's Griffin, 2017).

Tested by Joe Yonan.

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