Easy Mushroom Omelet Recipe with Sautéed Onions
Light yet satisfying, this easy mushroom omelet recipe combines sautéed cremini mushrooms, onions, thyme, and a touch of balsamic vinegar with egg whites in a tender no-flip omelet full of savory flavor.
Servings: 2 servings, 1 omelet
Calories: 161kcal
Equipment
Ingredients
- 1 tablespoon butter salted or unsalted
- 1 cup thinly sliced yellow onion about 1/2 large
- Kosher salt divided use
- 2 cups sliced cremini (baby bella) mushrooms 4-6 ounces
- 1 1/2 teaspoons balsamic vinegar optional
- 1 teaspoon fresh thyme leaves
- 6 large egg whites
- 2 tablespoons milk 2% or 1%
- 1 teaspoon Dijon mustard
- 1/8 teaspoon ground black pepper
- 2 tablespoons coarsely chopped fresh parsley for garnish
Instructions
- Cook the onions. Melt the butter in an 8- to 10-inch nonstick skillet over medium heat. Add the onion and season with a pinch of salt. Sauté, stirring occasionally, for around 7-8 minutes or until softened and beginning to turn lightly golden.
- Cook the mushrooms. Add the mushrooms and cook, stirring occasionally, for 5-6 minutes, or until all of the liquid evaporates, and the mushrooms are soft and beginning to brown.
- Add the balsamic vinegar. Stir in the balsamic vinegar and thyme, if using, and cook for 30 seconds longer. Remove from the skillet, transfer to a bowl, and set aside. Wipe out the skillet, if needed.
- Prepare the egg mixture. In a medium mixing bowl, whisk together the egg whites, milk, mustard, 1/4 teaspoon kosher salt, and black pepper.
- Cook the eggs. Generously coat the same skillet with cooking spray and place over medium heat. When hot, add the egg mixture and cook until the edges start to set.
- Tilt the pan. Carefully slide a rubber spatula under a portion of the omelet’s edge, then tilt the pan slightly toward the spatula so some of the uncooked egg flows beneath the edge of the forming omelet. Repeat around the edge of the omelet a few times until most of the egg mixture is set.
- Add filling and cover. Spoon the mushroom mixture over one half of the cooking egg. Cover, reduce heat to medium-low, and continue cooking until the eggs are fully set on top, around 2-3 minutes.
- Fold and finish. Using a wide spatula, loosen the underside of the omelet that doesn’t have the onion mixture, fold it in half to enclose the onion mixture, cover the pan, remove from heat, and let rest for 1 minute.
- Serve. Slide the omelet onto a plate and garnish with chopped parsley. For 2 servings, cut the omelet in half.
Notes
Make ahead: The mushroom mixture can be prepared ahead, covered, and refrigerated for up to 2 days. Reheat gently before adding to the omelet.
Success Tips:
Cook off the mushroom moisture. Let the mushrooms release their liquid, then evaporate it so the filling isn’t watery.
Use a nonstick skillet. This helps the omelet release cleanly without tearing.
Keep the heat moderate. Too high, and the eggs can toughen.
Don’t skip the tilting step. Allowing the uncooked egg to flow beneath the edges of the omelet helps strengthen them, making the edges less likely to tear when folding or sliding the omelet from the pan.
Let the eggs fully set. Carton egg whites can take a little longer to cook and may release more moisture, so keep the pan covered until the top is completely set before folding.
Nutrition
Calories: 161kcal | Carbohydrates: 13g | Protein: 13g | Fat: 7g | Saturated Fat: 4g | Polyunsaturated Fat: 0.3g | Monounsaturated Fat: 2g | Trans Fat: 0.2g | Cholesterol: 17mg | Sodium: 238mg | Potassium: 648mg | Fiber: 2g | Sugar: 7g | Vitamin A: 588IU | Vitamin C: 13mg | Calcium: 71mg | Iron: 1mg