Kosher Quiche Recipe

Ingredients

• 1 1/4 cups all-purpose flour , sifted for light texture
• 1/2 teaspoon kosher salt
• 1/2 cup cold unsalted butter , cut into small cubes
• 3 to 4 tablespoons ice-cold water
• 4 large eggs , preferably from a kosher-certified source
• 1 cup whole milk or half-and-half, chilled
• 1 cup shredded kosher Swiss or mozzarella cheese
• 1/2 cup diced onions , sautéed for sweetness
• 1/2 cup chopped fresh spinach , wilted and drained
• 1/2 cup sliced mushrooms , sautéed to remove excess moisture
• 1 teaspoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 1/4 teaspoon ground nutmeg, optional for warmth