In a large skillet, heat 2 tablespoons of extra-virgin olive oil over medium heat. Add finely chopped medium shallots along with a pinch of kosher salt, and sauté for about 5 minutes until the shallots are softened and translucent, but not browned.

Next, stir in 8 ounces of sliced portobello mushrooms into the skillet. Cook for about 7 to 10 minutes, stirring occasionally until the mushrooms are tender and have released their moisture.

While the mushrooms are cooking, bring a large pot of salted water to a boil. Add 8 ounces of pappardelle pasta and cook according to package instructions until al dente, usually about 8 to 10 minutes.

Once the mushrooms are ready, lower the heat and stir in minced garlic, fresh rosemary, crushed red pepper, tomato paste, and balsamic vinegar into the skillet. Cook for 2 to 3 minutes until the mixture is well combined and aromatic.

After draining the pappardelle, add it directly to the skillet with the mushroom ragu. Toss gently to ensure each ribbon is evenly coated with the savory sauce.

To plate, serve generous portions of the pappardelle in bowls, finishing with a sprinkle of shaved Parmigiano Reggiano or Parmesan cheese on top.