This is a really useful base for building meals on - so many things seem to start with cooking onions down until soft and flavoursome. More often then not, that's the pain with cooking meals; the time-consuming and tedious bits that seem to get in the way of the enjoyable main event (and I do mean the cooking and not just the eating, honestly). Try this, then. These slow-cooked onions can be used as the foundation for several meals and even kept in the freezer. If you take the package out in the morning to defrost, you can then skip quite a few steps when it's time to prepare supper. Six onions is quite a nice quantity to do - it will easily provide for three or four meals and doesn't take much work from you.
6 onions, halved and thinly sliced
200ml dry sherry
Melt the butter and turn the sliced onions in the fat. Bring to a sizzle, then stir well and pour in the sherry. Mix thoroughly and cover the pan. Turn down the heat and cook for an hour or so, stirring occasionally. Remove the lid, turn up the heat and bubble to reduce any excess liquid. Allow to cool, then divide into portions and chill or freeze.
Last night I used a good 400g of the onions to form the basis of a simple onion tart; a ravishing supper for a cold autumn evening. Put your slow-cooked onions into the bottom of an 8" pastry case, then pour over two eggs beaten with seasoning and a small carton of crème fraîche. Bake for 30 minutes at 200°c and serve warm.