Wash the potatoes and cook in boiling water for 15-20 minutes. Wash tomatoes, radishes and peppers. Halve the peppers, clean them and cut them into rhombs. Cut tomatoes in half. Clean and quarter the radishes.
Cut the sheep's cheese into cubes. Peel the garlic and press it into the yoghurt using a garlic press. Mix yoghurt, lemon juice and olive oil and season with salt, pepper and a little sugar.
Drain the potatoes, peel and let them cool down. Cut Lollo Rosso leaves from the stalk and wash them. Put 8 leaves of iceberg lettuce aside, cut the rest of the lettuce into small pieces. Wash the watercress and remove the leaves.
Wash the basil and parsley, dab dry and remove the leaves. Cut the potatoes into slices. Peel onion and cut into thin rings. Peel and halve the avocado and cut into slices.
Arrange vegetables, herbs, watercress, lollo rosso, sheep's cheese and anchovy fillets on iceberg lettuce boats. Serve with the yoghurt and olive oil dressing.