Tart-sweet oranges, fresh rosemary, and crushed fennel seeds add a subtle herb-citrus flavor to broiled salmon fillets. Make the marinade up ahead of time and store seperately until ready to use. The mild acidity of fresh orange juice cuts the richness of salmon. Be careful not to marinate longer than 20 minutes; as in ceviche, the citrus marinade can "cook" the fish. Crush the fennel seeds with a mortar and pestle, or place them in a zip-top plastic bag on a cutting board and crush with a heavy pan. You can prepare the marinade up to one day in advance and refrigerate in in an airtight container until ready to use.