For gorgonzola and walnut ravioli you can use spicy or sweet gorgonzola, depending on whether you prefer a milder or sharper flavour; and, when mixing everything together, to make it creamier you could add 2-3 tablespoons of mascarpone or ricotta. Finally, cook the ravioli in plenty of boiling salted water for a few minutes, as soon as they come to the surface they are ready; then drain thoroughly, being careful not to break them.