Bring salted water to a boil in a large pot, add pasta and cook until tender. Drain, toss with olive oil and set aside.
While your pasta is cooking clean your mushrooms by using a damp paper towel to gently wipe off any dirt, then slice mushrooms.
Coat the bottom of a dutch oven or heavy bottom pan with olive oil and bring to a medium heat. Add shallot/onion and garlic. Cook for 5 min while stirring occasionally. Add sliced mushrooms and continue to cook for 8-10 min. Season with salt, pepper, Italian seasoning and crushed red pepper flakes. Add balsamic vinegar to the mushroom mixture and cook for 5 min.
Plate the cooked pasta and top with the prepared marinara sauce and cooked mushrooms. Sprinkle with fresh chopped parsley and shredded parmesan cheese if desired.
