Cook the ravioli in a large pot of boiling salted water until just cooked through, about 5 minutes. Drain and put on a platter.
Meanwhile, cook the butter in a heavy medium frying pan over medium-high heat until pale golden, about 4 minutes. Add the basil leaves and cook until lightly fried, about 2 minutes. Add the pine nuts. Pour over the cooked ravioli. Grate 1/2 teaspoon of nutmeg directly over ravioli. Sprinkle Parmesan over dish and serve.