These slow-cooked caramelized onions and mushrooms are rich in flavor and can be served on their own or paired with other favorite dishes.
If you've ever caramelized onions, then you know the aroma is pure heaven! It's sweet and comforting all at the same time.
I equally love the aroma of caramelizing mushrooms. Earthy and fragrant... simply mouthwatering.
These caramelized onions and mushrooms will not only fill your kitchen with a wonderful aroma, but they will leave you wanting to add them to many of your favorite dishes.
Why you will love these
- With simple ingredients, the natural flavors of the mushrooms and onions shine.
- Extremely versatile - can be used in so many other dishes such as casseroles, pasta, soups, and more. See all of my suggested uses below.
- Minimal prep and just one pan, so cleanup is easy.
- Make ahead and store for several days in the refrigerator.
If you love mushrooms, try Mushroom Ravioli with Sage Butter, Spinach Artichoke Dip Stuffed Portobello Mushrooms, and Mushroom Brie Quiche.
- Mushrooms - I prefer cremini (baby bellas) for their deeper flavor, but white or button mushrooms can also be used.
- Onions - Sweet yellow onions are best for caramelizing. Red onions can also be used.
- Thyme pairs beautifully with mushrooms. Tarragon or rosemary are also tasty. Use fresh for optimal flavor.
Please see the recipe card for complete instructions and ingredient amounts.
- To clean the mushrooms, use a damp paper towel to brush off any dirt.
TIP: Do not clean mushrooms by dipping them in water or holding them under running water. They are very porous and will become water-logged and soggy.
- Cut into thin slices. (Image 1)
- Heat a large skillet over medium heat. Add butter. When melted add the sliced mushrooms. (Image 2)
- Cook, stirring occasionally, for 8-10 minutes until brown. Season with salt and pepper and thyme. (Image 3)
- Stir together and transfer to a plate.
TIP: Wait to salt the mushrooms until after they have released their excess moisture. Salting the mushrooms at the beginning will draw out their moisture which will cause them to steam and not brown.
- While the mushrooms are cooking, cut the onions into thin slices. (Image 4)
- Add the butter to the same skillet used to cook the mushrooms.
- Add the onions, stirring to coat with the butter. (Image 5)
- Reduce the temperature to medium-low and cook for 20-30 minutes, stirring occasionally, until soft and golden brown. (Image 6)
TIP: If the onions start to dry out, add 1-2 tablespoons of water as needed.
- Season with salt and pepper. Add the mushrooms back to the pan and toss with the onions. If desired, stir in 1 teaspoon of Worcestershire sauce for added flavor.
Why are the onions and mushrooms cooked separately?
Onions and mushrooms cook at different rates. Onions take longer to caramelize than mushrooms do.
Also, mushrooms contain water, and this moisture needs to cook out and evaporate before the mushrooms can start to brown.
Cooking them separately is the key to developing the best flavor and texture of each ingredient. Then, simply toss them together and serve.
These golden brown flavor bombs are delicious as a side dish on their own. They are also equally delicious as a complement to other dishes.
A large, wide skillet is best. It provides a large surface area which will help the onions to caramelize more quickly.
No, covering the pan will trap moisture which causes the onions and mushrooms to steam, not brown.
More vegetable recipes to try
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Caramelized Onions and Mushrooms with Thyme
- 8 ounces cremini mushrooms (or button mushrooms)
- 3 tablespoons unsalted butter (divided)
- 2 small-med sweet yellow onions (approx. 2 cups sliced)
- 1-2 teaspoons fresh thyme leaves
- salt and black pepper (to taste)
- Use a damp paper towel to brush any dirt off of the mushrooms. (Note 1)
- Cut into thin slices. Heat a large skillet over medium heat. Add 1 tablespoon of butter. When melted add the sliced mushrooms.
- Cook, stirring occasionally, for 8-10 minutes until brown. Season with salt and pepper and thyme. Stir together and transfer to a plate.
- While the mushrooms are cooking, slice the onions into thin slices.
- Add the remaining 2 tablespoons of butter to the same skillet used to cook the mushrooms. Add the onions, stirring to coat with the butter. Reduce the temperature to medium-low and cook for 20-30 minutes until soft and golden brown. (Note 2)
- Season with salt and pepper. Add the mushrooms back to the pan and toss with the onions. (Note 3)
- Do not clean mushrooms by dipping in water or holding them under running water. They are very porous and will become water-logged and soggy.
- If the onions start to dry out, add 1-2 tablespoons of water as needed.
- Stir in 1 teaspoon of Worcestershire sauce for added flavor if desired.
- Store in an airtight container in the refrigerator for 3-4 days.
Nutritional information is an estimate and will vary depending upon the exact amounts and specific ingredients used.