1.Combine rind, juice, oil and half the chives in a small jug. Season to taste.
2.Make cocktail sauce. Combine ingredients in a small bowl. Cover; refrigerate until needed. (Makes 2 cups)
3.Shell and devein prawns, leaving tails intact.
4.Cut radicchio into 20 wedges, then arrange wedges on a large platter; drizzle with a little of the lemon dressing.
5.Combine prawns, avocado and remaining lemon dressing; spoon prawn mixture onto lettuce wedges, then dollop with large spoonfuls of cocktail sauce. Scatter with remaining chives and micro herbs.
6.Serve any remaining cocktail sauce in a small bowl on the side.
Cocktail sauce can be made up 2 days ahead.Note