Ingredients

  • 1 tablespoon olive oil plus additional for brushing baking pan and parchment paper
  • 1/2 lb turkey sausage, casings discarded (if necessary) and sausage coarsely crumbled
  • 2 large garlic cloves, chopped
  • 4 scallions, chopped
  • 1/2 lb fresh shiitake mushrooms, stems discarded and caps chopped
  • 1/2 lb fresh cremini mushrooms, trimmed and chopped
  • 1/4 teaspoon black pepper
  • 3/4 teaspoon salt
  • 1 (10-oz) package frozen chopped spinach, thawed and squeezed dry
  • 1/4 cup water
  • 2 large whole eggs
  • 4 large egg whites
  • 2 tablespoons fat-free (skim) milk
  • 1 oz finely grated Parmigiano-Reggiano (about 1/3 cup)
  • 3 oz Gruyere, coarsely grated (1 cup)
  • a 19- by 13-inch sheet of parchment paper

Method

  • Put oven rack in middle position and preheat oven to 350°F. Lightly oil a 15- by 10-inch shallow baking pan, then line bottom and all 4 sides with parchment paper, allowing 2 inches of parchment to hang over short sides of pan, and lightly brush parchment (except overhang) with oil.
  • Heat 1 teaspoon oil in a 12-inch heavy nonstick skillet over moderately high heat until hot but not smoking, then cook sausage, stirring, until finely crumbled and cooked through, about 2 minutes. Transfer to a bowl and keep warm, covered.
  • Add remaining 2 teaspoons oil to skillet and saute garlic and scallions, stirring, until golden, about 3 minutes. Add mushrooms, pepper, and 1/4 teaspoon salt and saute, stirring, until mushrooms are softened and golden, about 8 minutes. Add sausage and spinach to skillet and saute, stirring, 3 minutes. Transfer half of spinach mixture to a food processor and add water, then blend until finely chopped. Return to skillet, stirring to combine, and keep warm, covered.
  • Blend whole eggs, whites, milk, Parmigiano-Reggiano, and remaining 1/2 teaspoon salt in a blender until smooth and frothy.
  • Pour egg mixture into baking pan and bake until firm, about 10 minutes. Remove from oven and leave oven on.
  • Sprinkle egg layer evenly with half of Gruyere, then spoon spinach filling evenly on top and sprinkle with remaining Gruyere. Bake just until cheese melts, about 5 minutes.
  • Position pan on a work surface with a long side nearest you, then gently roll up egg layer toward you, using parchment as an aid and holding filling in place with your fingers.
  • Cool roll in pan on rack 10 minutes, then transfer to a platter using 2 large spatulas. Trim ends and gently cut into 8 slices with a serrated knife.