Cut avocado into halves and remove stones. Remove pulp and mix with lemon juice. Then mince thoroughly to make puree. Chop onion, garlic, add 1 teaspoon Worcestershire sauce, then add 6 tablespoons yogurt, salt and ground pepper. Beat well until homogeneous mass, add avocado puree and stir. Put in 2 small round sauce bowls.
Boil cauliflower in salted water, so as to preserve crispness, break it into florets. Clean sweet pepper, remove seeds and dice. Cut cucumber and radish onto circles.
Place each sauce bowl on a separate serving platter and space vegetables around.