Name: Spinach and Mushroom Baked Frittata
Prep time: 15 min
Cook time: 25 min
Total time: 40 min
Cuisine: American
Ingredients: 8 large eggs; 4 large egg whites; ¼ cup unsweetened 1% low-fat milk; 1 tsp olive oil; 8 oz cremini mushrooms, sliced; 1 small yellow onion, finely diced; 2 cloves garlic, minced; 5 oz baby spinach, roughly chopped; 2 oz feta cheese, crumbled; ½ tsp dried thyme; ¼ tsp salt; ¼ tsp black pepper, freshly ground; 2 tbsp fresh chives, chopped, for topping

Spinach and Mushroom Baked Frittata

A golden, oven-baked frittata packed with sautéed mushrooms and spinach, ready in about 40 minutes for a low-carb breakfast that can fit your meal plan.

By the Diabetic Plate kitchen November 13, 2026

MealBreakfast

Prep15 min

Cook25 min

Total40 min

Serves4

There is something comforting about a breakfast that comes out of the oven in one pan. This spinach and mushroom baked frittata is our answer to busy weekday mornings. It is low in carbs, low in sugar, and simple enough to make before you have finished your first cup of coffee.

A frittata is a lot like an omelet, except you finish it in the oven instead of folding it in a pan. That means you do not have to stand over the stove flipping eggs. You cook the mushrooms and spinach on the stovetop, pour in the egg mixture, and let the oven do the rest.

Why This Breakfast Works for Blood Sugar

Breakfast is one of the meals where many people with diabetes find blood sugar is hardest to manage. We built this recipe around eggs, egg whites and non-starchy vegetables, which are some of the gentlest foods you can eat in the morning. Mushrooms, onion and spinach add bulk and flavor with only a few grams of carbohydrate per serving.

We also kept the sugar very low. The only natural sugar comes from a little milk and the vegetables, so each serving stays well under 6 grams. There is no added sugar, honey or syrup in this dish.

Simple Ingredients You Probably Already Have

You do not need anything fancy for this frittata. Most grocery stores carry everything in the ingredient list, and the spinach and mushrooms are easy to find in the produce section. Feta adds a salty, tangy bite, so a small amount goes a long way. If you prefer a milder flavor, you can use a little less or leave it off the top.

Eggs and egg whites: the base of the dish, with extra whites to keep the fat lower.
Mushrooms and spinach: cook down quickly and add earthy flavor and fiber.
Feta and chives: a little goes a long way for flavor.

Making the Frittata Step by Step

Start by heating the oven and whisking your eggs. Then brown the mushrooms in a skillet with a teaspoon of olive oil. Browning them until they are dry and golden is the key step, because it keeps the frittata firm instead of watery. Add the onion, garlic and spinach, pour in the eggs, and bake until the center is set.

The frittata is done when it no longer jiggles in the center and reads 160°F on an instant-read thermometer. Let it rest for a few minutes, then cut it into wedges.

Make It Ahead for the Week

This recipe is a great make-ahead option. Cut the leftover wedges and store them in the fridge for quick breakfasts or lunches. A quick reheat in the microwave makes a satisfying meal in less than two minutes. We hope this frittata becomes one of your go-to easy breakfasts.

Ingredients (4 servings)

8 large eggs

4 large egg whites

¼ cup unsweetened 1% low-fat milk

1 tsp olive oil

8 oz cremini mushrooms sliced

1 small yellow onion finely diced

2 cloves garlic minced

5 oz baby spinach roughly chopped

2 oz feta cheese crumbled

½ tsp dried thyme

¼ tsp salt

¼ tsp black pepper freshly ground

2 tbsp fresh chives chopped, for topping

Instructions

Heat the oven. Set your oven rack to the middle position and preheat the oven to 375°F. Whisk the whole eggs, egg whites, milk, thyme, salt and pepper in a large bowl until smooth and no streaks remain.

Brown the mushrooms. Heat the olive oil in a 10-inch oven-safe skillet over medium heat. Add the mushrooms and cook 6 to 7 minutes, stirring now and then, until they are golden and the liquid has cooked off.

Add onion and spinach. Stir in the onion and cook 3 to 4 minutes until soft. Add the garlic for 30 seconds, then add the spinach by handfuls and stir until it wilts, about 2 minutes. Spread the vegetables evenly across the pan.

Pour and top. Pour the egg mixture over the vegetables and gently tilt the pan so it covers everything. Scatter the feta on top and let the edges set for 2 minutes on the stove.

Bake until set. Move the skillet to the oven and bake 18 to 22 minutes, until the center is set and no longer jiggles and an instant-read thermometer reads 160°F. Let it rest 5 minutes, then sprinkle with chives and cut into 4 wedges.

Tips

Squeeze excess moisture out of the cooked spinach with the back of a spoon so the frittata does not turn watery.

Use an oven-safe skillet with a handle that can handle 375°F. If the handle is plastic, wrap it in foil before baking.

Cook the mushrooms until dry and browned. This builds flavor and keeps the texture firm instead of soggy.

Storage: Cool completely, then refrigerate in an airtight container for up to 4 days. Reheat individual wedges in the microwave for 60 to 90 seconds or in a 325°F oven for about 10 minutes until warm through.

Spinach and Mushroom Baked Frittata

Why This Breakfast Works for Blood Sugar

Simple Ingredients You Probably Already Have

Making the Frittata Step by Step

Make It Ahead for the Week