Step 1

Bring a large pot of lightly salted water to a boil. Cook linguine at a boil until tender yet firm to the bite, about 11 minutes, adding frozen peas during the last 2 minutes of cooking time. Drain pasta and peas, reserving 1 cup cooking liquid.

Step 2

While the pasta is cooking, heat butter and olive oil in a large skillet over medium-high heat. Add mushrooms and onion; cook until mushrooms are brown, 5 to 7 minutes.

Step 3

Season chicken with salt and pepper. Cook in the same skillet over medium-high heat until browned and no longer pink, 7 to 10 minutes. Add the mushrooms back to the skillet. Add cream cheese, lemon juice, and lemon zest; stir until cream cheese is melted. Remove from heat.

Step 4

Fold in Parmesan and Pecorino Romano cheeses, then parsley. Toss with pasta and peas, adding reserved cooking liquid as necessary to make a sauce.