Cook linguine according to package instructions. Drain, but reserve ½ cup of water for later.

Meanwhile, place the Italian sausage in a large skillet. Cook over medium-high heat, stirring occasionally, until sausage is fully cooked. Drain any excess grease from skillet; set cooked sausage aside.

Using a large, deep skillet, add the olive oil and place over medium-high heat. Once hot, add the mushrooms. Cook, stirring often, for 5-6 minutes, or until mushrooms have begun to soften and turn brown. Add the onions, garlic, oregano, salt and pepper. Cook for 2 more minutes, stirring often.

Add peas and chicken stock; continue cooking for 3-4 minutes, stirring often.

Add cream and cooked Italian sausage from Step 2. Reduce heat to a low simmer; cook for 8-10 minutes, stirring occasionally.

Remove skillet from heat and add cooked linguine and Parmesan cheese. Toss to coat, adding a small amount of pasta water to adjust thickness of sauce (if necessary). Garnish with a sprinkle of dried parsley before serving (optional).

Serve hot.