- 3/4 pound spaghetti
- 3 teaspoons olive oil
- 8 ounces button mushrooms, halved
- kosher salt and black pepper
- 1 head radicchio, torn
- 4 ounces fontina, grated (about 1 cup)
- 2 tablespoons Dijon mustard
- chopped fresh chives, for serving
- Cook the spaghetti according to the package directions; drain and return it to the pot.
- Meanwhile, heat the oil in a large skillet over high heat. Add the mushrooms, ½ teaspoon salt, and ¼ teaspoon pepper. Cook, tossing often, until browned, 5 to 7 minutes.
- Add the mushrooms, radicchio, fontina, mustard, and ¼ teaspoon each salt and pepper to the pasta and toss to combine.
- Serve topped with the chives.