My Family's Easy Spinach Quiche Recipe

Ingredients

• 1 ½ cups (190g) all-purpose flour
• ½ cup (115g) unsalted butter, chilled and cubed
• 1 tablespoon granulated sugar
• 1/4 teaspoon salt
• 4-5 tablespoons ice water
• 2 cups (150g) fresh spinach, chopped
• 1 tablespoon olive oil
• 1 medium onion, finely chopped
• 3 large eggs
• 1 cup (240ml) whole milk
• 1 cup (100g) grated cheese (Gruyère, cheddar, or a blend)
• 1/4 teaspoon nutmeg
• Salt and pepper to taste