Boil the potatoes in salted water for 10 - 15 minutes or until tender.
Drain, cut in half and keep warm.
For feta cheese coating, mix the ingredients together and pour over the potatoes.
For the caramelised onion, heat the butter in a heavy-based frying pan.
Add the onion and sugar and sauté until the onion is translucent.
Add the port and allow to simmer for 2 minutes.
Spoon potatoes and cheese dressing into a serving bowl and top with the onions.