pan-fry the mushrooms
In a bowl, combine cream cheese and shredded parmesan cheese. Set aside until needed. Place a large pan over high heat. Add the butter and olive oil. When the butter melts, add the diced onion and sliced mushrooms. Pan-fry for 5 - 8 minutes or until the mushrooms are brown and pan-fried.
cook the pasta
While the mushrooms are pan-frying, cook the pasta according to the package instructions. Preserve 1 1/4 cup pasta cooking water.
Add diced garlic, sprig of thyme and chopped parsley to the mushroom sauce. Cook for a minute, lower the heat and add the reserved water, cream cheese mixture, and grated lemon zest. Stir to combine and remove from the heat.
Add the cooked pasta, toss to combine, and serve. Divide the Creamy Mushroom Pasta between four plates. Optionally serve with additional shredded parmesan cheese, grated lemon zest, and chopped parsley.