Heat olive oil, shallots, and a pinch of salt in a large skillet over medium heat. Stir frequently until shallots are softened but not browned.
Add mushrooms and cook until they gain color. Stir and add ½ teaspoon salt, cooking until the mushrooms become tender and their liquid evaporates.
Cook pasta in salted boiling water according to package instructions until al dente. Reserve ¾ cup of pasta water, then drain the pasta.
Add garlic, rosemary, red pepper, tomato paste, vinegar, and butter to the mushroom mixture. Stir in ½ cup of pasta water and continue to cook until saucy.
Add the drained pasta to the pan, tossing to coat with the sauce. Add more pasta water if needed to achieve the desired consistency.
Shave Parmesan curls over the pasta using a vegetable peeler and serve.
Prep Time: 15 minutes
Cook Time: 15 minutes
Total Time: 30 minutes
Kcal: 394 kcal
Servings: 4 servings