Crustless Salmon, Leek & Mushroom Quiche

Preheat oven to 375°F. Coat a pie pan with cooking spray. Line a rimmed baking sheet with parchment paper.

Place 1 (5½-ounce) salmon fillet on the prepared baking sheet. Drizzle with 2 teaspoons oil and bake until the fish flakes easily with a fork, 10 to 15 minutes, depending on the thickness of the fillet. Let cool slightly; flake the fillet with a fork.

Meanwhile, place the remaining 1 tablespoon oil in a large skillet; heat over medium heat. Add ½ cup leek; cook, stirring, until slightly softened, about 1 minute. Add 2 cups mushrooms, 1 cup spinach and ¼ teaspoon salt; stir to combine. Cook, stirring occasionally, until the vegetables are tender and any liquid released from the vegetables has evaporated, 5 to 8 minutes. Set aside to cool slightly.

Add the flaked cooked salmon to the vegetables and combine. Transfer to the prepared pie pan and spread in an even layer. Whisk 5 eggs, 1 cup milk and the remaining ¼ teaspoon salt in a large bowl. Pour the egg mixture over the vegetables. Sprinkle with 1 tablespoon dill.

Bake until the top starts to turn golden brown and the center is set, 35 to 40 minutes. Let stand for 10 minutes before slicing. Garnish with lemon zest, if desired.