Spinach Pie

This spinach pie is made with eggs, caramelized onions, gruyere cheese, and golden puff pastry. An easy side dish idea for Thanksgiving or a family dinner!

Course Side Dish
Cuisine American
Keyword Spinach Caserole, Spinach Casserole Puff Pastry, Spinach Casserole Recipe
Prep Time 10 minutes
Cook Time 1 hour
Total Time 1 hour 10 minutes
Servings 6
Calories 711 kcal
Author Stephanie


  • 4 tablespoons salted butter (1/2 stick)
  • 2 large yellow onions
  • 3 cloves garlic minced
  • 2 10 oz. packages frozen spinach
  • 5 large eggs separated
  • 1 tablespoon breadcrumbs (Italian or plain)
  • 1 cup Gruyere cheese shredded
  • ¾ cup Parmesan cheese shredded
  • 2 springs fresh thyme or 2/3 teaspoon dried
  • ½ teaspoon dried sage
  • Salt/Pepper to taste
  • 2 sheets puff pastry thawed in fridge overnight.
US Customary - Metric


  1. Note: Let the puff pastry thaw in the fridge overnight. Don't unroll it frozen. Don't let it sit at room temperature for too long as it can affect it from rising.

Caramelize the Onions

  1. Heat the butter in a medium saucepan over medium heat.
  2. Cut the onions into ½ inch pieces, don’t dice too finely. They shrink down as they cook.
  3. Heat the onions for 15 minutes, decrease the heat to medium-low, and continue to cook until they’re brown and caramelized. This takes about 35 minutes total but is worth it for the flavor. Note: If time doesn’t allow for this, use one onion instead and soften for 7 minutes.

  4. Add the minced garlic and cook for an additional minute.

Prepare the Casserole Filling

  1. Preheat the oven to 400 degrees.
  2. Drain the water from the spinach.

  3. Egg wash: Crack ONE of the eggs into a small bowl and add 1 tablespoon water. Whisk and set aside.
  4. In a large bowl, crack the remaining 4 eggs. Whisk vigorously until well-combined. (Air pockets are created from whisking well which makes a fluffier consistency.)
  5. Add the spinach, breadcrumbs, cheese, thyme, sage, salt, pepper, and cooked onions/garlic. Stir until well-combined.
  6. Lightly grease a 9 x 13 inch casserole dish. Roll out one thawed puff pastry until it is large enough to cover the bottom and sides.
  7. Add the spinach filling.
  8. Roll out the second puff pastry sheet until it is large enough to cover the top.
  9. Use a fork to create indentations around the edges of the casserole dish.
  10. Brush the top of the casserole with the egg wash, don’t let it drip down the sides as that can affect rising.

  11. Create slits on the top to allow steam to escape.
  12. Bake for 35 minutes, or until the top is a nice golden brown.
  13. Let it sit for 5 minutes prior to serving.

Recipe Notes

Make Ahead Method:

Mix the filling ingredients up to 2 days ahead of time and store in an airtight container until ready to bake.

Proceed with assembling the casserole with the puff pastry and bake as instructed.

Nutrition Facts
Spinach Pie
Amount Per Serving
Calories 711 Calories from Fat 441
% Daily Value*
Fat 49g75%
Saturated Fat 18g113%
Cholesterol 151mg50%
Sodium 635mg28%
Potassium 502mg14%
Carbohydrates 47g16%
Fiber 5g21%
Sugar 3g3%
Protein 23g46%
Vitamin A 11684IU234%
Vitamin C 9mg11%
Calcium 477mg48%
Iron 5mg28%
* Percent Daily Values are based on a 2000 calorie diet.