Shell and devein shrimp. Place shrimp in food processor with egg, cream and pepper. Puree to smooth mousse. Place puree in large mixing bowl and add remaining ingredients. Fold ingredients gently until blended. Shape mixture into 10-12 cakes, place on plastic wrap and refrigerate (up to 1 hour). Heat 2-3 TBS oil in skillet and saute crab cakes, several at a time, until golden brown (about 3-4 minutes on each side). Remove to serving platter and keep warm. Serve with avocado butter. 4 servings.
Because of the quantity of lime juice used, this recipe can actually be made several hours ahead, and will still retain its bright green color.
Place avocado and lime juice in food processor and blend until the texture of butter. Serve in dollops with crab cakes.