Caramelized Onions and Mushrooms

These caramelized onions and mushrooms are my go-to side dish for steak nights or to spoon over creamy polenta. The recipe brings together pantry staples and transforms basic vegetables into a sweet savory luxurious topper that goes with just about anything. All you need is patience and a bit of stirring to get deep golden caramelization that works wonders in burgers grain bowls or even as a pizza base.

I started making this when I wanted steakhouse flavors at home without the price tag. Now my family requests it for holidays and burger nights alike because it really feels like something special even on a busy weeknight.

Ingredients

• Unsalted butter: Gives the base richness Choose a high butterfat variety for best flavor
• Olive oil: Helps prevent the butter from burning Use a fruity extra virgin
• Garlic: Adds a fragrant kick Pick fresh and mince it yourself
• Mushrooms: The mix of baby Bella and shiitake makes the flavors more complex Go for firm dry mushrooms that are evenly sliced
• Yellow onions: When slowly cooked these become sweet and jammy Pick onions that feel heavy for their size
• Kosher salt: Brings out the moisture but add it gradually and taste as you go
• Thyme: Adds earthiness Fresh is ideal but dried works too
• Coarse black pepper: Provides balance and a little bite Use freshly ground for the best punch
• Honey: Enhances natural sweetness and helps develop browning Local honey will have the best flavor
• Worcestershire sauce: Gives a savory meaty oomph Look for one with minimal additives
• Balsamic vinegar: Brings tangy richness and lovely color Choose a syrupy aged version if you can
• Chicken broth: Adds moisture and umami If you wish you can swap for vegetable beef or even a dry white wine

Step-by-Step Instructions

Melt the fats:

Add unsalted butter and olive oil to a large Dutch oven set over low heat. Let the butter gently melt together with the oil to coat the bottom of the pot and keep it from browning too quickly.

Bloom the garlic:

Stir in minced garlic and let it soften for about one minute while you stir continuously until the aroma is noticeable and the garlic starts to look golden and translucent. This helps build the base flavor without burning.

Add onions and mushrooms:

Increase the heat to medium and add in all of your sliced onions and mushrooms at once. Let them sit uncovered and undisturbed for about five minutes. This contact with the hot pan gets you started on browning.

Begin seasoning:

Sprinkle in kosher salt black pepper and the thyme at this stage. Give everything a stir so the seasoning touches as much surface area as possible and each slice gets evenly coated.

Build deeper flavor:

Raise the burner to medium high. Pour in Worcestershire sauce honey balsamic vinegar and chicken broth. Toss everything together to combine well then continue to cook stirring every five minutes or so.

Caramelize and reduce:

Continue to cook uncovered and stirring every five minutes. Let the liquid fully simmer and reduce. Keep going for forty five to fifty minutes until the onions and mushrooms are deep golden soft no liquid is left at the bottom and the edges begin to turn brown and crisp.

Taste and finish:

Taste and adjust salt or pepper if needed. Let the onions and mushrooms sit for a minute off the heat to develop extra flavor. Serve warm or keep for later.

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Fresh thyme is my favorite part because it adds such an herbal lift and reminds me of late summer in my grandmother’s garden. Every time I make this my kitchen immediately smells like Sunday dinners growing up and my mom’s laugh as she always sneaked a taste straight from the pan.

Storage Tips

Store in an airtight container in the refrigerator for up to five days. Reheat gently in a skillet over medium low heat to restore the texture. For longer storage freeze flat in a zip top bag for up to three months then thaw overnight in the fridge.

Smart Ingredient Swaps

If you do not have shiitake mushrooms substitute with all baby Bella or white mushrooms. For a vegan version use vegetable broth and swap honey for maple syrup. Shallots can replace half the onions for an even sweeter profile.

Serving Suggestions

This side dish is delicious on top of grilled steak or chicken in a French dip sandwich or over a simple ricotta toast. Try spooning it onto baked potatoes or stirring into cooked quinoa for a hearty vegetarian lunch.

A Bit Of Backstory

Caramelized onions have been a staple in European and Asian kitchens for centuries bringing rich umami flavor to dishes like French onion soup and biryanis alike. Combining them with mushrooms is popular for vegetarian and kosher cuisines as it amplifies that meaty flavor without actual meat.

Frequently Asked Questions

→ What type of mushrooms can I use?

Baby Bella and shiitake mushrooms are recommended, but any combination of your favorite mushrooms works well.

→ How do I achieve rich caramelization?

Cook the onions and mushrooms slowly over medium-low heat, allowing their natural sugars to develop color and flavor.

→ Can I substitute broth flavors?

Absolutely. Use chicken, beef, vegetable broth, or even a splash of white wine for different depths of flavor.

→ Is it possible to make this dish ahead?

Yes. Prepare and cool, then refrigerate in an airtight container for up to five days. Reheat gently before serving.

→ How do I serve these caramelized onions and mushrooms?

They are perfect with grilled meats, tossed with pasta, spooned over toast, or served alongside roasted vegetables.