Caramelized Onions and Mushrooms for steak- the only side dish you’ll need with grilled steak and they couldn’t be easier to make. This simple recipe elevates any steak dinner.
I make these sauteed mushrooms and onions again and again because they’re easy to make, taste restaurant quality and I can whip up a batch in under 15 minutes.
Personally I haven’t found a better side with grilled steak than this. I guess that’s why it’s one of my favorite recipes.
Why I make this with every steak dinner:
- It elevates any steak I grill or pan sear to restaurant level.
- Easy recipe for the best sauteed mushrooms and onions
- Takes just minutes to make and only a few simple ingredients.
Ingredients needed to make Caramelized Onions and Mushrooms:
- baby bella mushrooms (can also use white mushrooms)
- yellow onion
- olive oil
- butter
- salt and pepper
- Worcestershire sauce
Optional garnish: 2 tablespoons fresh parsley, finely chopped
Best way to clean mushrooms:
There are a couple different way to clean mushrooms and a lot of discussion about whether to wash or just wipe them.
I wipe mine with a damp paper towel or sometimes a pastry brush if there’s a lot of dirt on them.
If you rinse them, be sure to dry them really well. Wet or moist mushrooms will affect the caramelization process – the end game for all the flavor. To rinse them, use the ‘shower’ option on your kitchen faucet to get most of the debris off.
You can also fill a bowl with water and dunk them – just don’t soak them in water – they’ll get spongy.
Either method – dry them well before cooking.
Tips for the best mushrooms and onions:
- Butter – olive oil combination for cooking. Olive oil keeps the butter from browning too quickly. Butter adds rich flavor you can’t get from olive oil.
- Season near the end of cooking with salt and black pepper. The salt draws moisture from the mushrooms if you add it early and makes it harder to caramelize them.
How to make Caramelized Onions and Mushrooms:
Peel and thinly slice the onion then slice mushrooms 1/4 to 1/2″ thick.
Add olive oil and butter to a large skillet over medium heat to medium-high heat. Swirl so it coats the bottom of the pan. Add mushrooms in a mostly single layer then scatter the onions over the top.
Cook mushrooms (uncovered) without stirring for 3-4 minutes. Check and once the bottoms are a little brown, season with salt, black pepper and Worcestershire sauce and give it a good stir.
Reduce heat to medium low – low and continue cooking 3-5 minutes stirring occasionally until the mushrooms reach your preferred color and the onions are tender.
Taste and adjust seasonings as needed then serve right away.
What to serve with these mushrooms:
- Pan Seared Steak
- Grilled Marinated Steak
- Juicy Grilled Burgers
- Blend with risotto for elevated flavor.
- Slow Cooker Pot Roast.
Storage and reheating:
Store leftover mushrooms in an airtight container in the fridge up to 3 days. Reheat in the microwave at 30 second intervals or in a skillet over low heat.
Subs and variations:
- Sub Portobello or even morel mushrooms in this recipe.
- Sub soy sauce or balsamic vinegar for Worcestershire sauce.
- Add fresh herbs – thyme, rosemary and parsley – or minced garlic.
- Pour in a splash of dry red or white wine.
- Red onions in place of yellow.
Enjoy!
Caramelized Onions and Mushrooms
Equipment
- large skillet
Ingredients
- 8 ounces baby bella mushrooms sliced 1/4-1/2" thick (can sub white mushrooms)
- 1 medium onion thinly sliced
- 1 1/2 tablespoons olive oil
- 1 1/2 tablespoons butter
- 1/2 teaspoon salt or to taste
- 1/4 teaspoon pepper or to taste
- 1 tablespoon Worcestershire sauce
Optional Garnish:
- 2 tablespoons fresh parsley finely chopped
Instructions
Cleaning the Mushrooms:
- Whatever method you use to clean the mushrooms, it’s very important to dry them well. Wet or moist mushrooms will affect the caramelization process.
- If your kitchen faucet has a ‘shower’ option lightly spray the debris from the mushrooms OR fill a large bowl with room temp water and plunge them quickly, turning to remove the dirt.
- Transfer them to a clean cotton towel and dry them well before cooking.
Cooking Onions and Mushrooms:
- Peel and thinly slice the onion then once the mushrooms are clean and dried well, slice the mushrooms 1/4 to 1/2″ thick (or thicker if you prefer).
- To a large skillet over medium - medium-high heat add the olive oil and butter. Once the butter melts, swirl it around the bottom then add the mushrooms in as much of a single layer as your skillet will allow.
- Scatter the onions over the top of the mushrooms.
- Let the mushrooms saute (uncovered) without stirring for 3-4 minutes. This is the hardest part because the tendency is to stir.
- Check them and once the bottoms are golden brown, season with salt and pepper, add the Worcestershire sauce and give it all a good stir.
- Reduce to medium low/low heat and continue cooking 3-5 minutes more, stirring occasionally until the mushrooms reach your preferred color and the onions are tender.
- Taste and adjust salt as needed then serve right away.