Cava Pickled Onions

Combine vinegar, cava and sugar in a saucepan and heat until sugar is dissolved, set aside and let cool slightly. Peel onions and cut into rough slices.
Put the onions in a pickling glass and press them down a bit. Put the spices in the glass and pour over the Cava mixture to cover. Put it in the fridge and let them sit overnight, and preferably a week.
Will keep for quite a long time, use common sense and you will be fine. Try with other spices such a chili, coriander, garlic! Everything works with this recipe!