Sautéed mushrooms and onions are the perfect, versatile side dish! With just a few simple ingredients, easy sautéed mushrooms and onions pair perfectly with grilled steak, as a juicy burger topping, or as a savory side dish for any protein.

They’re also super easy to make and are ready in under 15 minutes. This is one of our favorite easy side dishes for steaks. 

sauteed mushrooms and onions in a black cast iron skillet

Ingredients for Sautéed Mushrooms and Onions

  • 3 Tbsp. butter or olive oil 
  • 1 pound sliced white mushrooms or mushrooms of choice
  • 1 sweet yellow onion – sliced
  • 1/2 tsp. salt
  • 1/2 tsp. pepper
  • 2 Tbsp. Worcestershire sauce

How to Sauté Onions and Mushrooms

Making sautéed mushrooms and onions is so simple, you’ll be done in under 15 minutes from start to finish:

  1. In a skillet, melt the butter over medium-high heat.
  2. Add the mushrooms and cook for 5 minutes – they should begin to sweat and brown.
    raw mushrooms in a cast iron skillet with a wooden spoon for sauteed mushrooms and onions
  3. Reduce heat to medium, add the sliced onion, salt, pepper, and Worcestershire sauce and cook for another 5-7 minutes, stirred frequently, or until the onions are soft and brown.
    mushrooms and onions cooking in a black cast iron skillet with a wooden spoon for sauteed mushrooms and onions

Tips for making Mushrooms and Onions

  • Please be careful not to burn the melting butter.  If you do so, you will have to start all over.
  • Cook the mushrooms over medium-high heat.  Since they release a lot of moisture so they must be cooked over high heat and stirred constantly so they do not burn.
  • Add the onions when the mushrooms are cooked to turn golden brown around the edges and translucent.
  • Add the garlic in the end.  Reduce the heat to low and stir frequently.  Garlic burns easily and there is nothing worse than the taste of burnt garlic.

Is Mushroom a Vegetable?

In culinary terms, mushrooms are somewhat treated like a vegetable. they are used as a savory ingredient in recipes, usually alongside meats or vegetables.

Many times, they are used as meat substitutes, such as a grilled Portabello mushroom cap. In scientific terms, mushrooms are not a vegetable, they are an edible fungus.

Are Mushrooms Good for you?

We love the fact that mushrooms are very healthy for you! Mushrooms are packed with nutritional value, from fiber and protein to important nutrients like Vitamin B and D.

They’re also a great source of protein for those on a plant-based diet. Onions are low in calories and also contain fiber and important nutrients.

Sautéeing mushrooms and onions in butter does not overly saturate them, so they’re still a great source of your daily vegetable intake. 

Can you Freeze Mushrooms and Onions?

Yes! You can freeze mushrooms. After sautéeing the mushrooms and onions you can let them cool, then transfer to an air-tight container and freeze for up to three months.

To reheat, simply let them thaw in the refrigerator, then reheat in a skillet with a few tablespoons of butter over medium heat until warmed.

Sauteed mushrooms and onions in a skillet with a wooden spoon, ready to serve

Mushroom Side Dish Recipe

Mushrooms and onions make the perfect savory side dish. Sauteed mushrooms and onions for steak take a regular steak to an over the top experience!

They also make a great topping for your burgers, like on top of this Mushroom Swiss Burger.

Prime Rib side dishes are always a great addition to your holiday table. If you’re looking for an easy side dish this holiday season that’s also savory and delicious, sautéed mushrooms and onions are definitely for you. They require minimal ingredients, a short cook time, and can be frozen for later use for up to three months! You can’t get much simpler than that!

You must try our easy mushroom and onion recipe with some of our favorite Prime Rib Recipes:

  • Slow Roasted Prime Rib Recipe
  • Boneless Prime Rib Roast
  • Standing Rib Roast

Try topping some of our favorite grilled steak recipes with this onions and mushrooms recipe:

  • Grilled Chuck Steak
  • Picanha Steak
  • Reverse Sear Ribeye
  • Porterhouse Steak
  • Steak Foil Pack
  • Steak Diane

How to Reheat a Steak|How to Reheat Prime Rib

You can make our recipe for mushrooms and onions and add thinly sliced pieces of steak and heat for approximately 3-5 minutes. You will love this recipe for steak bites! They are so good that no one will know you are serving leftovers.

We are in love with our easy Mushroom Risotto Recipe side dish! It is truly the perfect side dish!

Recipe Tip: We used white mushrooms in this recipe but, we also love shiitake mushroom or baby portobello mushrooms if preferred. Shiitake mushrooms and portobello are a great substitute in this recipe.

Love cooking plant-based recipes? Try these vegetarian mushroom recipes…

  • Mushroom Grilled Cheese and French Onion Soup
  • Vegetarian Stuffed Mushroom Recipe
  • Instant Pot Risotto
  • Vegetarian Stuffed Mushroom Recipe
  • Air Fryer Mushrooms
  • Hungarian Mushroom Soup
  • Baked Portobello Mushrooms

Chicken and Mushroom Recipes

  • Chicken Breast and Mushroom Recipe
  • Chicken and Mushroom Pie
  • Chicken Tetrazzini

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sautéed mushrooms and onions in a black cast iron skillet

Sautéed Mushrooms and Onions

Using only a few SIMPLE ingredients, quick and easy sautéed mushrooms and onions are the PERFECT versatile side dish for steak, burgers, chicken or pork!
4.84 from 6 votes
Print Pin Comment
Course: Side Dish
Cuisine: American
Keyword: mushroom recipe, mushrooms and onions, sautéed mushrooms and onions
Prep Time: 5 minutes
Cook Time: 10 minutes
Total Time: 15 minutes
Servings: 6
Calories: 91kcal
Author: Jennifer Shreckengost


  • 3 Tbsp. unsalted butter
  • 1 pound white mushrooms sliced
  • 1 sweet yellow onion sliced
  • 1/2 tsp salt
  • 1/2 tsp pepper
  • 2 Tbsp. Worcestershire sauce


  • In a skillet, melt the butter over medium-high heat, then add the mushrooms and cook for 5 minutes. 
  • Next, reduce heat to medium, add the sliced onion, salt, pepper, and Worcestershire. Cook for another 5-7 minutes or until the mushrooms and onions are soft and browned. 
  • Serve warm. 



  • Don’t let the Mushrooms and Onions dry out! If the mushrooms and onions soak up too much of the juices, you can add additional Worcestershire sauce 1 teaspoon at a time. 
  • Do not replace the sweet yellow onion with white or red, you want to use only a sweet yellow onion for this dish. 
  • Variety of Mushrooms: We used white mushrooms in this recipe but, we also love using shiitake mushroom or baby portobello mushrooms if preferred. 


Calories: 91kcal | Carbohydrates: 7g | Protein: 2g | Fat: 6g | Saturated Fat: 3g | Cholesterol: 15mg | Sodium: 251mg | Potassium: 345mg | Fiber: 1g | Sugar: 4g | Vitamin A: 185IU | Vitamin C: 4.9mg | Calcium: 20mg | Iron: 0.8mg
Tried this recipe?Mention @familyfoodie or tag #SundaySupper!

This post was updated on November 5, 2019.