spinach quiche recipe

**Ingredients:** - 1 pre-made pie crust - 1 tablespoon olive oil - 1 small onion, finely chopped - 3 cloves garlic, minced - 5 oz fresh spinach, roughly chopped - 1 cup shredded cheese (cheddar, Swiss, or Gruyère) - 4 large eggs - 1 cup half-and-half (or milk for a lighter version) - 1/2 teaspoon salt - 1/4 teaspoon black pepper - 1/4 teaspoon ground nutmeg (optional)