If you love a good egg recipe, then you'll love this easy mushroom frittata using beautiful healthy vegetables, eggs, cream, and cheese.

Close up of cooked mushrooms, tomatoes and spinach inside a frittata

Mushroom Frittata Overview

This mushroom frittata couldn't be easier to make! Chopped mushrooms, tomatoes, spinach and cheese are added to a pie dish. Eggs are beaten with cream and poured over top creating a savory flavor. This is baked in the oven for a delicious, healthy meal.

This frittata is the perfect easy egg dish to serve guests. I recommend pairing it with my overnight french toast casserole or sheet pan pancakes.

But don't just save this recipe for a special occasion. You can also use it as meal prep breakfasts or lunches for the week. Cut into slices and store in the fridge or freezer for individual meals.

Eggs, bowls of chopped tomatoes, onion, spinach, shredded mozzarella, mushrooms, heavy cream, and spices.

Recipe Ingredients

1 cup diced yellow onion
1 cup chopped baby spinach
1 cup cherry tomatoes - sliced in half
½ cup shredded mozzarella cheese - cheddar or parmesan will also work
½ cup sliced mushrooms
8 large eggs
½ cup heavy cream - you can also use greek yogurt or sour cream
½ tsp ground mustard
½ tsp garlic powder
½ tsp salt
¼ tsp ground black pepper

Four images of a quiche dish, first with chopped onion, second with added chopped spinach, third with chopped tomatoes, fourth with shredded mozzarella and sliced mushroom.

How To Make A Mushroom Frittata

Full ingredients and instructions are also in the recipe card at the bottom of this blog post.

STEP 1: Preheat the oven to 350°F. Spray the 9" quiche pan or 9" deep pie dish with nonstick cooking spray. Place the quiche pan on top of a baking sheet.

STEP 2: Add 1 cup diced yellow chopped onion, then sprinkle 1 cup chopped baby spinach over top.

STEP 3: Next, arrange 1 cup sliced small tomatoes, followed by ½ cup shredded cheese and ½ cup sliced mushrooms.

Two images of a bowl with eggs, cream and spices dumped in, one image unmixed, second ingredients beaten together

STEP 4: In a medium bowl whisk together 8 large eggs, ½ cup heavy cream, ½ tsp ground mustard, ½ tsp garlic powder, ½ tsp salt and ¼ tsp ground black pepper.

Two images of a mushroom spinach tomato frittata, first one is unbaked, second one is baked.

STEP 5: Gently pour the egg mixture around the vegetables. This will help the veggies to stay in place. You can rearrange them using a fork if they move.

STEP 6: Now bake for 40-45 minutes or until a toothpick comes out clean when poked through the center.

STEP 7: Remove from oven and let cool. Slice and serve with your favorite toppings such as hot sauce, salsa, avocado, or sour cream.

A slice of vegetable quiche, with slices of avocado, grape tomato and a fork

Recipe Tips

The secret to making a beautiful frittata is arranging the vegetables in the dish beforehand. The egg custard is then gently poured around them. Once baked it creates a beautiful presentation.
To prevent the frittata from sticking, be sure to grease the dish with a bit of oil or nonstick cooking spray before adding the ingredients.
Add the pie dish onto a baking sheet then add it directly to the oven. It helps to avoid spills while carrying the frittata and during the baking process.

How To Store

Fridge – Add leftovers to the fridge in an airtight container for up to a week.
To Freeze – To freeze, wrap each serving individually in plastic wrap or tightly inside parchment paper. Then place each serving inside a large Ziploc freezer bag or airtight container. This will keep in the freezer for up to 3 months.
To Reheat – This recipe can be reheated in the oven at 350°F or in the microwave.

Flavor Variations

KALE – Instead of spinach you can try kale. Just chop it small into bite-size pieces.
BELL PEPPERS – Dice them and add to the cooking dish along with the other ingredients.
GREEN ONIONS – An easy addition to any frittata, quiche or omelet.
HAM – An easy addition. Chop into bite-size pieces first.
HERBS - fresh or dried herbs like fresh thyme, basil or rosemary always brighten up the flavor of eggs.
BACON – Cook in a skillet over medium-high heat and slice small, then add to the frittata.
GRATED PARMESAN – Fresh grated parmesan cheese adds an earthy flavor that goes great with eggs.

Can I use different cheese? Medium and old cheddar cheese would work well for this frittata. You could also use white cheddar, and parmesan or feta cheese.

Is ground mustard the same as yellow mustard sauce? While both are made from ground mustard seed, they are actually quite different. A jar of yellow mustard sauce also contains water, vinegar and other ingredients. I do not recommend adding it to the egg base as it will change the consistency of your frittata. But yellow mustard can be used as a sauce after the frittata is baked!

What's the difference between a frittata and a quiche? These two are very similar, however with a slight difference. A quiche is baked in a pastry crust (or pie crust) while a frittata has no crust and is baked directly in a dish. A frittata can sometimes also be known as a crustless quiche. Frittata usually includes ingredients mixed in a bowl with eggs. This can be cooked on the stove in a pan or baked in the oven.