These Mushrooms & Cipollini Onions in Wine-Butter Sauce are a riff on the dish at The Outback. Quick, easy to assemble and rich in texture and flavor, this side is perfect for both weeknights and holiday entertaining!
1poundBaby Bella Mushrooms- washed, trimmed and halved if large in size
2TBSExtra Virgin Olive Oil, divided
3 ½TBSButter, not melted and divided
2heaping TBSParsley- chopped
1PoundsCipollini Onions– peeled, trimmed and halved if large in size
Salt and Pepper, to taste
1CupDry White Wine
Adjust an oven rack to the center position. Preheat to 375 degrees F. Prepare a large baking sheet with aluminum foil
Toss the mushrooms with 1 tablespoon of olive oil and melted butter. Season with salt and pepper. Transfer the mushrooms to the prepared sheet pan, cut or stem side down. Add the Thyme and Rosemary sprigs on top of the mushrooms.
Roast the mushrooms and herbs in the oven for 15 minutes, or until the mushrooms release their liquid. Drain the mushroom liquid into a container and set both aside (you will need the liquid for the sauce).
Reduce oven temperature to 350 degrees F.
Melt 3 tablespoons butter with the remaining 1 tablespoon oil in a large cast iron skillet (or nonstick sauté pan) over medium heat. Add the onions, partially cooked mushrooms and sprigs of herbs. Toss to coat and season with salt and pepper.
Transfer skillet to the oven and roast, tossing (or stirring gently) occasionally an additional 30 minutes, or until the vegetables are tender and caramelized.
Meanwhile, Make the Sauce: In a small saucepan melt remaining ½ tablespoon butter over medium heat. Add the garlic and season with salt and pepper. Sauté until fragrant, about 30 seconds.
Add the reserved mushroom cooking liquid and the wine. Bring contents to a simmer and cook until liquid is thickened and reduced by half, about 10 - 15 minutes. Add the cornstarch and stir it into the sauce. Taste and adjust for seasoning.
Discard the thyme and rosemary sprigs. Toss with the sauce and parsley. Serve immediately.
*Do not wash your mushrooms, instead use a dampened paper towel or a pastry brush to remove dirt.