reserve 2 cups of
pasta cooking water, though
all might not be used

source, 6 servings
1 lb pasta, cooked in salted water; 1 c ricotta, 1 c grated parm, zest & juice of 2 lemons, kosher salt & pepper, red pepper flakes, basil
heat ricotta, parm, zest & juice, salt, pepper; add pasta water, starting with 1 c; stir; add pasta; top with more parm, red pepper flakes, basil, black pepper