This Simple Spinach Leek & Onion Frittata recipe is a rustic frittata that’s formal enough to serve for a brunch gathering, but also casual enough to serve for a quick and easy weekend breakfast, lunch or dinner. 

A cookie sheet filled with spinach leek frittata.

This spinach frittata transforms the most humble of ingredients into a delicious and hearty breakfast, brunch or a quick weeknight dinner.  

A cookie sheet filled with baked eggs with pan roasted tomatoes on top.

What Is An Egg Frittata? 

Frittata’s are like an Italian style open-faced omelet or a French style crustless quiche.  They’re typically cooked slowly on the stovetop then finished in the oven.   

Spinach Frittata Recipe

This Simple Spinach Leek & Onion Frittata is one of my favorite frittatas to make.  I’m partial to the hash brown crust!

  • Unsalted butter or vegan butter
  • Extra-virgin olive oil
  • Hash browns (pre-cooked)
  • Onion
  • Leek
  • Free range brown eggs
  • Cream or whole milk
  • Gruyere cheese
  • Parmesan cheese
  • Baby spinach leaves
  • Salt and freshly ground black pepper to taste
  • Cherry tomatoes

Find printable recipe with measurements below.

Variations

  • Sprinkle in fresh thyme and parsley
  • Broccoli and cheddar 
  • Asparagus
  • Arugula or kale instead of spinach
  • Sweet potato hash browns

How To Make A Frittata

This spinach frittata recipe comes together in about 30 minutes start-to-finish.

  1. Mix eggs, cream and cheese.  Combine eggs, cream and cheese in a medium bowl. Blend with a whisk or fork.
  2. Cook hash browns.  Cook hash browns in a medium ovenproof skillet over medium low heat until golden and crispy and set aside.  
  3. Saute onion and leek.  Cook onion and leek in skillet until the onions turn golden brown and are lightly caramelized.
  4. Add spinach.  Sprinkle the chopped spinach leaves in the pan.
  5. Egg, dairy and cheese mixture.  Pour in egg mixture; stir gently to distribute spinach, onion and leek evenly.
  6. Cook eggs.  Cook until eggs are partially set, about 5-6 minutes.
  7. Bake eggs in oven.  Uncover skillet, and bake eggs for another 3-5 minutes or just until the center is set and the eggs are cooked through. Be careful not to overcook your frittata.
  8. Remove from oven.  Remove spinach frittata from oven and loosen from the skillet.
  9. Serve.  Cut spinach frittata into 8 wedges.

Baking Frittata On A Cookie Sheet

  1. Follow steps 1 – 7 then sprinkle the hash browns to the bottom of a cookie sheet.
  2. Distribute the onion and leek mixture over the hash browns.
  3. Sprinkle the top with chopped spinach.
  4. Pour the egg mixture over the top of the spinach.
  5. Place the cookie sheet in oven and cook for 5-7 minutes or just until the center is set and the eggs are cooked through.

Tips For Making Frittatas

  • A well seasoned cast iron skillet works best for frittatas
  • For every dozen eggs you use, you’ll about need 1/2 cup milk or cream
  • Frittatas make great use of those leftovers in your refrigerator.  Potatoes, rice, quinoa, beans or vegetables
  • If you’re starting from scratch, you want to make sure that whatever you’re adding to your frittata is fully cooked
  • When adding vegetables, you’ll want to saute them separately so they don’t add extra liquid that’ll water-down your frittata 
  • If you’re adding breakfast potatoes or hash-browns from scratch, make sure they’re fork tender (they won’t cook much more when the egg mixture is added)
  • A good frittata should have the texture of custard (just barely set)
  • If you want a browed top for your frittata, you can stick it under the broiler for a few minutes, but keep a close eye on it
  • After your eggs have barely cooked, you can finish cooking the frittata in the oven set to 350 degrees for 8-10 minutes or so.

A cookie sheet filled with baked eggs with hashbrowns.

How To Make Pan Roasted Tomatoes

I love pan roasted tomatoes and I garnish a lot of meal with them.  They add a pretty pop of freshness, flavor and color to any dish…even frittatas!  Check out how easy they are to make…

  • Heat 2 tablespoons olive oil to a pan.
  • Add the tomatoes and cook for over medium-low heat for about 1-2 minutes or until they begin to soften.

You can also stir in some minced garlic and fresh basil ribbons for a nice touch.

A cookie sheet with a baked spinach leek and onion frittata with pan roasted tomatoes on top.

More Breakfast Recipes

Simple Spinach, Leek & Onion Frittata
Yield: Serves 8

Simple Spinach, Leek & Onion Frittata

Prep Time 10 minutes
Cook Time 10 minutes
Total Time 20 minutes

This Simple Spinach Leek & Onion Frittata is formal enough to serve for a brunch gathering, but also casual enough to serve for a quick and easy weeknight dinner.

Ingredients

  • 2 tablespoons unsalted butter
  • 5 tablespoon extra-virgin olive oil, divided
  • 1 cup cooked hash browns
  • 1 large onion, peeled,  cut in half and sliced thin
  • 1 large leek, trimmed, rinsed well and sliced thin
  • 8-10 free range brown eggs
  • 3 tablespoons cream or whole milk
  • 1/4 cup gruyere cheese
  • 3 tablespoons parmesan cheese
  • 1/2 cup baby spinach leaves
  • salt and freshly ground black pepper to taste
  • 1 cup cherry tomatoes

Instructions

  1. Preheat oven to 350 degrees.
  2. Combine eggs, cream and cheese in a medium bowl. Blend with a whisk or fork.
  3. Heat 2 tablespoons oil in a medium ovenproof skillet over medium low heat.
  4. Cook hash browns until they're golden and crispy. Remove from pan and set aside. Wipe pan clean.
  5. Add the butter and 1 tablespoon oil to the pan.
  6.  Add the sliced onion to the pan. Reduce heat to low and cook slowly, stirring occasionally for about 15 minutes or until the onions turn golden brown and are lightly caramelized.
  7. Add the leek and cook until tender and lightly browned for about 3 minutes.
  8. Sprinkle the chopped spinach leaves in the pan.
  9. Add egg mixture; stir gently to distribute spinach, onion and leek evenly.
  10. Cover skillet and cook until eggs are partially set, about 5-6 minutes.
  11. Uncover skillet, and bake for another 3-5 minutes or just until the center is set and the eggs are cooked through. Be careful not to overcook your frittata.
  12. Remove from oven and loosen the frittata from the skillet.
  13. Cut into 8 wedges.

If using a cookie sheet

  1. Follow steps 1 - 7 then sprinkle the hash browns to the bottom of a cookie sheet.
  2. Distribute the onion and leek mixture over the hash browns.
  3. Sprinkle the top with chopped spinach.
  4. Pour the egg mixture over the top of the spinach.
  5. Place the cookie sheet in oven and cook for 5-7 minutes or just until the center is set and the eggs are cooked through.

For the Pan Roasted Tomatoes

  • Heat 2 tablespoons olive oil to a pan.
  • Add the tomatoes and cook for over medium-low heat for about 1-2 minutes or until they begin to soften.

Notes

  • A well seasoned cast iron skillet works best for frittatas
  • For every dozen eggs you use, you’ll about need 1/2 cup milk or cream
  • Frittatas make great use of those leftovers in your refrigerator.  Potatoes, rice, quinoa, beans or vegetables
  • If you’re starting from scratch, you want to make sure that whatever you’re adding to your frittata is fully cooked
  • When adding vegetables, you’ll want to saute them separately so they don’t add extra liquid that’ll water-down your frittata 
  • If you’re adding breakfast potatoes or hash-browns from scratch, make sure they’re fork tender (they won’t cook much more when the egg mixture is added)
  • A good frittata should have the texture of custard (just barely set)
  • If you want a browed top for your frittata, you can stick it under the broiler for a few minutes, but keep a close eye on it
  • After your eggs have barely cooked, you can finish cooking the frittata in the oven set to 350 degrees for 8-10 minutes or so.