Well done on using fennel for salmon, keep on trying other recipes. I grew up in Czechoslovakia, and we used a lot of dill in sauces, pickled gherkins, cucumber salad etc. I never knew what fennel was then. Yesterday my neighbour Nicky gave me a lot fennel tops to use. So I tried them with salmon steaks and pesto sauce, in the absence of dill. My husband and I loved it, the taste is similar to dill, especially when it is cooked. The only small problem was that it was a little tough, even though I chopped it up fine. Today I used the raw tops chopped up finely in a tomato salad, again lovely.
In the absence of dill, I would use fennel tops for marinades, salads, salmon etc. Of course I like the licorice taste, unlike many other people who hate it. Zenka-Marie