Put the walnuts and garlic oil in a food processor and process to a paste, adding up to 1/2 cup warm water through the feeder tube to slacken the consistency. Spoon the mixture into a large bowl and add the cream. Beat well to mix, then season to taste with salt and black pepper.
Cook the pansotti or stuffed pasta in a large pan of salted boiling water for 4-5 minutes; according to the instructions on the packet. Meanwhile, put the walnut sauce in a large warmed bowl and add a ladleful of the pasta cooking water to thin it.
Drain the pasta and tip it into the bowl of walnut sauce. Toss well, then serve immediately.