Cook the pasta in rapidly simmering water until al dente.
While pasta cooks, spray the skillet with cooking oil spray and place over high heat. Add 1/4 cup water and “sweat” the mushrooms, covered for 2-3 minutes or until slightly wilted. Add the artichoke hearts and continue cooking, uncovered, until most of the liquid is gone, about 3 minutes.
Cut the cream cheese into several pieces and add them to the skillet with 1 cup of water or the reserved liquid from the canned artichoke hearts plus enough water to make 1 cup. With a wooden spoon, gently smooth the sauce while it comes to a simmer. Add the lemon juice and pepper, plus any additional water, if needed, to bring the sauce to a medium consistency.