Creamed King Trumpet Mushrooms & Spring Onions

 

8 spring onions (or 2 bunches scallions)

Extra-virgin olive oil, for sauteing

8 ounces king trumpet (aka king oyster, royal oyster, or royal trumpet) mushrooms

1 tablespoon salted butter

2 garlic cloves, finely grated (preferably on a Microplane)

1 1/3 cups heavy cream

Kosher salt and freshly ground black pepper, to taste

2 tablespoons chopped parsley or dill

Flaky salt, for sprinkling

 

Trim the ends of the onions or scallions, then halve them crosswise. If you’re using onions, halve the bulbs lengthwise. Slice the mushrooms about ¼-inch thick lengthwise. Using a paring knife, score one side of each slice with a crosshatch pattern. Set a large cast-iron skillet over medium-high heat and add enough oil to coat the bottom of the pan. Sear the mushrooms in a single layer (do them in batches if needed), pressing them flat if they start to lift or curl. Turn after 4 to 5 minutes, once burnished and golden, then season with salt. Cook the second side for another 3 to 4 minutes, until burnished and golden. Transfer the mushrooms to a plate and repeat if needed until all of the mushrooms are cooked. (If your mushrooms are unevenly sized, just flip and remove the smaller ones as soon as they’re ready.) Lower the heat to medium and add the butter. Once foaming subsides, add the spring onion or scallion bulb ends and season with salt. Press down to establish good contact with the pan. Cook for about 3 minutes, until starting to brown, then flip and add the green tops to the pan. Cook for another 5 to 7 minutes or so, turning everything halfway, until soft and browned in parts. (The scallions will cook faster than the spring onions, so just keep a close eye.) Sprinkle with salt and pepper. Turn the heat to low, then stir in the grated garlic. Add the cream and reduce for about 3 minutes. Stir occasionally, raising the heat if needed, until slightly thickened. Remove the pan from the heat and allow to cool for a few minutes (the sauce will thicken a bit further). Transfer the creamed onions to a platter or serve straight from the skillet. Add the mushrooms and spoon a little cream on top. Sprinkle with parsley or dill, then season with freshly ground pepper and flaky salt.