Step 1

Trim and thinly slice 1 pound cremini mushrooms into 1/4-inch pieces. Halve 1 large sweet Vidalia or yellow onion, then slice into 1/4-inch-thick half-moons. Mince 2 garlic cloves.

Step 2

Heat a large skillet over high heat. Add 2 tablespoons unsalted butter and 2 tablespoons olive oil. When the butter melts, add the mushrooms and 1/4 teaspoon of the kosher salt. Cook, stirring occasionally, until the mushrooms release their liquid and the liquid is almost evaporated, 5 to 10 minutes.

Step 3

Add the onion and season with the remianing 1/4 teaspoon kosher salt and 1/4 teaspoon black pepper. Cook, stirring occasionally, until the onions and mushrooms are tender and golden-brown in spots, 7 to 10 minutes. Meanwhile, finely grate the zest from 1 medium lemon until you have 1/2 teaspoon. Juice the lemon until you have 2 tablespoons. Pick and finely chop the leaves from 1/4 bunch fresh parsley until you have 2 tablespoons.

Step 4

Add the garlic to the onion and mushroom mixture and cook, stirring often, until golden and fragrant, about 1 minute. Add 1/4 cup dry white wine and cook until completely evaporated, 1 to 2 minutes.

Step 5

Remove the skillet from the heat. Add the lemon juice, lemon zest, and parsley, and toss to combine. Taste and season with more kosher salt and black pepper as needed.