The fresh salsa called for here has a natural low-sodium advantage over bottled commercial salsa, but if you don't want to make your own salsa, buy a container of fresh salsa from your grocery store deli section.
Fresh spinach, chicken, and a combination of cheeses make this pasta dish comforting enough for the last days of winter yet fresh enough for the first days of spring. Serve family style or portion out in individual ramekins. Either way, this penne pasta casserole is definitely worth sharing.
