Wash potatoes thoroughly and cook in boiling salted water for 15-20 minutes. Wash the tomatoes and remove the stalk. Cut tomatoes into quarters, remove seeds and dice. Peel and quarter the onion and cut into strips. Wash chives and cut into small rolls. Bring the stock to the boil, season to taste with vinegar, salt, sugar and pepper.
Stir in oil. Drain the potatoes, cut them in half lengthwise and add them to the marinade together with the onions, diced tomatoes and chives (some tomatoes and chives are retained). Peel, halve and stone the avocados and cut them lengthwise into slices. Sprinkle with lemon juice, season with salt and pepper. Arrange potato salad on plates, cover with avocado wedges and spread cream cheese on top. Serve sprinkled with the chopped nuts, remaining tomatoes and chives
Preparation time approx. 40 minutes