Preheat oven to 450 degrees F. On a large piece of buttered foil, place salmon and season with salt, spices, and aromatics. Dot with a bit of butter. Close up the foil into a packet. Place on a baking sheet. Bake for 10 to 15 minutes. Remove from oven and set aside.
for the salad and dressing:
Whisk the lime juice, mustard and honey. Drizzle in the olive oil and whisk until creamy. Taste. Whisk in more lime, mustard honey or olive oil if desired. Set aside.
Break up the watercress into smaller pieces, discarding large legs. Rip the sorrel into bite size pieces, removing the thick legs. Place both in a bowl.
Toss salad with dressing, reserving a bit for the salmon. Taste for salt. Plate the salads. Set each salmon fillet over the salad and spoon a little extra dressing over the fish.
Alternatively, let the fish cool completely. Break up the fish into chunks and toss with the salad.