Bring a large pot of salted water to a boil and cook the linguine according to package instructions until al dente. Drain the pasta, rinse briefly, and reserve ½ cup of pasta water for later. Set the pasta aside.
In a large skillet, heat 1 tablespoon of olive oil over medium-high heat. Add half of the minced garlic and sauté for 30 seconds until fragrant. Stir in the chopped onion and cook until softened, about 2 minutes. Add the mushrooms and fry until golden brown. Pour in 2 tablespoons of water to help release their flavor and create a light gravy. Transfer the mushrooms to a plate and set aside.
In the same skillet, heat the remaining tablespoon of oil. Add the rest of the garlic and sauté briefly. Add the shrimp and cook until they start to turn pink, about 1 to 2 minutes per side. Sprinkle in the red pepper flakes, paprika, and a pinch of salt. Stir well to coat the shrimp in the spices.
Return the sautéed mushrooms and onions to the skillet with the shrimp. Stir everything together for another minute to allow the flavors to come together. Transfer the entire mixture to a plate and set aside while you make the sauce.
In the same skillet, add the cream cheese and milk. Stir constantly over medium-low heat until the cream cheese melts and the mixture becomes smooth and creamy. Let it gently simmer for a few minutes to thicken slightly.
Add the grated Parmesan and shredded mozzarella into the cream sauce. Stir until both cheeses are melted and fully incorporated. Taste and adjust seasoning with a bit of salt if needed.
Return the shrimp and mushroom mixture to the pan along with the cooked pasta. Stir to coat everything in the sauce over low heat for about 2 minutes. Gradually pour in the reserved pasta water, a little at a time, until the sauce reaches your desired consistency. Garnish with chopped parsley and serve immediately.
Notes
Remember to cook your pasta at the same time as your sauce so that everything is hot, fresh and your pasta has no clumps! Originally Published January 28, 2015. Post updated with images and video.