Fry the onions, garlic and spices until lightly golden.
Place the potatoes back in the pan with the onions and add the tomatoes. Cook on a high heat to reduce the tomatoes slightly for about 3 minutes then add the spinach.
Remove from the heat straight away and gently toss the spinach so that it just wilts then add the vinegar and some of the chopped oregano or parsley.
Pour into a serving dish then crumble the feta cheese on top, sprinkle some olive oil, black pepper and more fresh herbs