Some charring enhances the flavor of the vegetables, so don’t be afraid of small spots that look a little burnt. To add a meaty element, after charring the sprouts, fry a couple of slices of bacon, use the rendered fat to cook the mushrooms, and add crumbled bacon to the skillet with the parsley. A good addition is fried eggs served on top or on the side.
2 tablespoons vegetable oil
1 pound Brussels sprouts, preferably about 1 ½ inches in diameter, trimmed and quartered through the core (about 3½ cups)
Salt and ground black pepper
2 pounds cremini mushrooms, wiped clean and quartered, or halved if small (about 12 cups)
1 tablespoon butter
2 medium onions, quartered lengthwise and each quarter quartered crosswise
1 large red bell pepper, cored, seeded, and diced into ½-inch pieces
1 tablespoon pressed or grated garlic (about 5 medium cloves)
1 teaspoon paprika
1/3 cup vegetable stock
1 teaspoon soy sauce
½ cup chopped fresh parsley
In a large cast-iron or nonstick skillet over medium-high heat, heat 1 tablespoon oil until shimmering. Add the Brussels sprouts and ¼ teaspoon salt, stir to coat, arrange them cut sides down, and cook, undisturbed, until lightly charred on the bottom, about 4 minutes. Stir the sprouts and continue to cook, stirring occasionally, until just barely tender, about 4 minutes longer. Scrape them into a bowl and set aside.
Return the skillet to medium-high heat, add the remaining 1 tablespoon of oil, and heat until shimmering. Add the mushrooms and ½ teaspoon salt and cook, stirring often, until liquid evaporates and mushrooms brown, about 10 to 14 minutes. Scrape the mushrooms into a separate bowl and set aside.
Return the skillet to medium heat, add the butter, and heat until melted. Add the onions, red pepper, and ¼ teaspoon salt and cook, stirring, until vegetables are soft and onions are turning golden, about 8 minutes.
Add the garlic and paprika and cook, stirring, until fragrant, about 40 seconds longer. Add the stock, soy sauce, mushrooms, ¼ teaspoon salt, and ground black pepper to taste and stir.
Adjust the heat to medium-high, spread the mixture into an even layer, and cook, undisturbed, until much of the moisture has evaporated and the mixture looks drier on top, about 9 minutes.
Add the Brussels sprouts, stir and scrape the bottom of the skillet to mix and incorporate any char on the bottom, spread into an even layer, and cook until the sprouts are tender, about 5 minutes longer.
Add most of the parsley and stir to incorporate. Adjust the seasoning with salt and ground black pepper if necessary and serve, sprinkling each serving with some of the remaining parsley.