This was very tasty, with the nutty walnuts playing off the nuttiness of the browned brussels sprouts, plus the cheese and the sweetness of the onions. Instead of boiling the sprouts, which did not sound very appealing, I used my food processor to chiffonade them-- a trick I learned from Biscuit over in the old Cook's Talk-- and then just sauteed them in the olive oil. This had great flavors, but it could have used a bit more sauce-- maybe a splash of cream, or I should have been more generous with the olive oil. I did add some of the water from cooking the pasta-- a little more would have helped. Otherwise a great recipe and a big hit with everyone (except the kid) including my visiting parents.