Wash the shrimps and pat them dry. Sprinkle with half of the lemon juice
Peel the garlic and press through. Wash the chives and cut into fine rolls. Mix mayonnaise, soured milk and garlic. Season to taste with salt and pepper. Stir in half the chives
Clean and wash lettuce and radishes. Pluck salad into pieces. Cut radishes into sticks. Cut avocados in half, remove the stone. Peel the halves. Cut the flesh into narrow slices. Sprinkle with remaining lemon juice immediately
Arrange everything with the sauce and sprinkle with the remaining chives. Garnish with a slice of lemon if desired.
Drink: cool white wine, e.g. Blanchet