White Bean and Mushroom Gratin

by becky
Created
From the cookbook America's Test Kitchen: More Meditteranean

Ingredients

  • 1/2 cup extra-virgin olive oil, divided
  • 10 oz cremini mushrooms, trimmed and sliced 1/2 in thick
  • 3/4 t salt
  • 1/2 t pepper, divided
  • 4–5 slices country-style bread, cut into ½-inch pieces (5 cups)
  • ¼ cup minced fresh parsley, divided
  • 1 cup water
  • 1 tablespoon all-purpose flour
  • 1 small onion, chopped fine
  • 5 garlic cloves, minced
  • 1 tablespoon tomato paste
  • 1½ teaspoons minced fresh thyme or ½ teaspoon dried
  • ⅓ cup dry sherry
  • 2 15 oz cans great Northern beans, undrained
  • 3 carrots, peeled, halved lengthwise, and cut into 3/4 in pieces

Directions

  1. heat oven to 300 degrees. Heat ¼ cup oil in 12-inch ovensafe skillet over medium-high heat until shimmering. Add mushrooms, salt, and ¼ teaspoon pepper and cook, stirring occasionally, until mushrooms are well browned, 8 to 12 minutes.
  2. While mushrooms cook, toss bread, 3 tablespoons parsley, remaining ¼ cup oil, and remaining ¼ teaspoon pepper together in bowl. Set aside. Whisk water and flour together in second bowl until no lumps of flour remain. Set aside.
  3. Reduce heat to medium, add onion to skillet, and continue to cook, stirring frequently, until onion is translucent, 4 to 6 minutes. Reduce heat to medium-low; add garlic, tomato paste, and thyme; and cook, stirring constantly, until bottom of skillet is dark brown, 2 to 3 minutes. Add sherry and cook, scraping up any browned bits.
  4. Add beans and their liquid, carrots, and flour mixture. Bring to boil over high heat. Off heat, arrange bread mixture over surface in even layer. Transfer skillet to oven and bake for 40 minutes. (Liquid should have consistency of thin gravy.)
  5. Leave skillet in oven and turn on broiler. Broil until crumbs are golden brown, 4 to 7 minutes. Remove gratin from oven and let sit for 20 minutes. Sprinkle with remaining 1 tablespoon parsley and serve.