Heat the oil in a skillet, add the onions and stir-fry over a high heat until lightly browned

Add 2 tablespoons water and the sugar, lower the heat and cook for 20-30 minutes until the onions are very very soft and caramelized

Sprinkle the vinagers and cook until they have evaporated

Pour in the wine and cook until about half has evaporated

Season with salt and pepper then break the eggs into the pan, one at the time and cook for a few minutes over medium heat

Transfer the eggs and their sauce to a warm serving dish and serve with toast