I used walnuts because I had a jar. I just coarsely pounded a couple of handfuls and threw them in. I also used red wine because I had some, and rosemary from the garden and a bay leaf. I think the walnuts added their own flavour, and the sauce was very popular.
It did not elicit moans of pleasure like these dishes sometimes can, and I guess that's where 30 years of experience comes in, but it was a tasty lunch using what was in the house, which was not much.