4 Servings
5 mins
5 mins
10 mins
In a heavy based pan sweat the onions in the oil for a few minutes until they soften.
Add the port, vinegar, sugar and salt and simmer the onions until they become translucent and the liquid has reduced to a thick syrup.
Transfer the onions to a sterile jar. They will keep in the fridge for up to 2 weeks.
Spread each piece of rye with butter.
On the unbuttered side of 4 pieces, spread a 5mm layer of liverwurst, a slice of cheese and a generous spoonful of onions.
Top each with another slice of rye with the butter on the outside.
Fry the sandwiches in a frying pan over a medium heat until they a lightly coloured and crunchy and the cheese has melted.
Serve immediately.
