Cut squash into long ribbons with a spiralizer or a knife.
Saute peppers and mushrooms in olive oil over medium high heat until mushrooms are golden and peppers are soft. Add squash ribbons and pesto. Cover and reduce heat to simmer. Cook 3-4 minutes.
Uncover and stir, adding Parmesan and seasoning to taste. Let Parmesan melt into noodles. Serves 2