I am making cioppino for Xmas dinner. This is a new recipe, and it's highly rated. It calls for fennel, which I dislike to a great degree. I saw some other recipes that call for leeks, so I got leeks. I have chopped them finely, and intended to caramelize them a bit with the onions in the recipe before adding tomatoes and stock and whatnot. Is there anything else that I should be thinking about? I don't have much experience with them, and would prefer to avoid destroying a $60 pot of soup.