The refreshing side salad is easy to make ahead: Prepare up to 12 hours in advance and refrigerate, covered. Serve cool or at room temperature with the baked salmon.
If the cranberry mixture gets too thick, add a tablespoon of water and whirl it around in the food processor. You can also make this in an 8-inch springform pan; it'll be very full, so you should cook over a foil-lined baking sheet. Cook time will be the same.