I did not have the Gruyere cheese, and used instead a cheese called La Creme De La Creme made in France by Supreme, of about 1/2 lb with the white covering removed and discarded. I used only 1/4 cup of half and half in place of the heavy cream because the cheese is so heavy in fat and cream. I grind the mustard seeds, so they would be very fresh tasting. I weighed the leeks before chopping, and after chopping. These leeks weighed more before the chopping. In other words, I weighed out 1 1/2 pounds both ways. I think a person writing down a recipe should take such into consideration, and note how many cups of leeks and about how many leeks (or other veggies). The chopped leeks weighing 1 1/2 pounds were around a cup and half less. Yes, they were weighed on a vegetable weight. I do not use black pepper because of the toxin in black pepper called piperine that contributes to arthritis. Piperine may have other health benefits, but those people that have cut it out of their diet suffers less with attacks of arthritis along with omitting chicken and eggs. Cayenne pepper is not the same in effects as black pepper. I rated this recipe a 5 star because other items on hand can be substituted for an item that one may be out of, and it is very healthy with leeks having so much potassium. A good way to use leeks instead of just the potato soup with leeks.