Prep 1 hr
Cook 35 mins
- 1⁄2 cup freshly grated pecorino romano cheese, plus more for the souffle dish
- 1 tablespoon extra virgin olive oil
- 6 ounces cremini mushrooms, trimmed, wiped clean, and finely chopped
- 1⁄4 cup finely chopped fresh flat-leaf parsley
- 1 teaspoon minced fresh rosemary
- 1 teaspoon minced fresh thyme
- 1 garlic clove, minced
- 2 teaspoons kosher salt
- fresh ground black pepper
- 3 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 1 cup milk
- 5 large eggs, separated, at room temperature
- cream of tartar (a pinch)
- Position oven rack in the center of oven; preheat oven to 400°.
- Generously butter an 8-inch souffle dish; sprinkle lightly with cheese, shaking the dish to coat evenly.
- Heat the oil in a large nonstick skillet over medium heat.
- Add in mushrooms; cook, stirring, until they begin to release their moisture.
- Increase heat to med-high; saute until the moisture evaporates, about 5 minutes.
- Stir in the parsley, rosemary, thyme, and garlic; saute for 1 minute.
- Add 1 teaspoon salt and a generous grinding of pepper; set aside to cool.
- Melt the butter in a small saucepan over low heat; add in flour; cook, stirring constantly, for 3 minutes.
- Gradually whisk in milk; bring to a boil, stirring constantly.
- Cook, stirring constantly, for 3 minutes; add in remaining 1 teaspoon salt and a grinding of pepper; remove from heat.
- In a big bowl, whisk the egg yolks until blended; whisk in a little of the white sauce to temper the eggs, then add the remaining sauce, whisking until blended.
- Add in mushrooms and cheese; stir.
- Add egg whites to a large bowl, then add in cream of tartar; beat slowly with an electric mixer until soft peaks form.
- Increase speed to high and beat until peaks are stiff and smooth.
- Using a rubber spatula, transfer about 1/3 of the egg whites to the mushroom sauce and gently fold in until blended.
- Add the remaining egg white to the sauce and gently fold in until blended; pour into prepared dish.
- Put the souffle in the oven and decrease temperature to 375°; bake until the souffle is puffed and golden, 30-35 minutes.
- If you like your souffle firm in the center, bake it for 5 minutes more; serve at once.