Easy Shrimp Alfredo

box penne

unsalted butter

extra virgin olive oil

yellow onion (diced)

red bell pepper (diced)

portobello mushrooms (roughly chopped)

garlic (minced)

medium/large shrimp (peeled, de-veined, tails off)

jar alfredo sauce

grated Romano cheese

heavy cream

cayenne pepper (to taste)

salt (to taste)

pepper (to taste)

chopped parsley (to garnish - optional)