Strain the hot tomato juice mixture into the gelatin. Measure the volume and stir in enough water to make a total volume of 4 cups liquid. Chill the aspic. When it is the consistency of raw egg whites, add 1 to 2 cups of any combination of the following:
1 Hass avocado, peeled and cut into 1/2-inch pieces
1 cup diced yellow bell peppers
1 fresh jalape├▒o pepper, seeded and minced (optional)
1 cup lump crabmeat, flaked
1 tablespoon chopped fresh cilantro or fresh basil
Rinse a 6- to 8-cup mold or bowl, then shake out the excess water. Pour in the aspic, cover, and refrigerate until set, about 3 hours. Unmold garnish with: