Soak gelatin in cold water; add boiling water and stir until dissolved. Add salt, onion, and vinegar. Add 3 tablespoons of this gelatin liquid to cottage cheese.
To remaining gelatin liquid, add tomato sauce. Pour half of tomato mixture into a lightly oiled mold; chill until set (Keep cottage cheese and remaining tomato mixture at room temperature.) and top with cottage cheese mixture. Chill until set and cover with the remaining tomato mixture.
To serve, unmold on slaw; garnish with pepper.
Yield: 4 to 6 servings