In mixing bowl, place salmon and add lemon juice, dill, shallots, olive oil, capers, red pepper flakes, salt, and pepper. Mix well, cover, and refrigerate for at least 1 hour for salmon to marinate.
In clean blender or food processor container, place avocado flesh, olive oil, lemon zest, lemon juice, and salt, and blend until smooth. Add water, 1 Tbsp at a time, if mixture is too thick to blend properly.
Working on one serving at a time, stuff salmon mixture to a depth of about 1 1/2 inches into either a ring mould, a 1 cup stainless steel measuring cup, a ramekin, or an empty tin can cut open at both ends. Unmould into shallow serving bowl and place some tomato broth around salmon. If using a mould such as a ramekin with only one open end, simply turn it upside down into bowl and lightly tap to release the fish. Top with avocado mousse.
Recipe Notes
Per serving: 439 calories; 29 g protein; 29 g total fat (6 g sat. fat); 13 g total carbohydrates (7 g sugars, 4 g fiberfiber); 603 mg sodium