Really rich onion & ale gravy

1. Heat the butter and oil in a frying pan. Once the butter is foaming, add the onions, sugar, thyme, if using, and a pinch of salt. Keeping the heat low, cook the onions for 45 minutes, covering halfway, until soft, golden brown and sticky.

2. Turn up the heat and cook the onions for 2-3 minutes more to get a dark caramel colour. Stir in the red miso, sizzle for 1 minute, then splash in the balsamic vinegar and let it reduce to almost nothing.

3. Stir in the flour and cook for 1 minute, or until it smells toasty, then gradually stir in the ale, a little at a time at first to avoid lumps. It will seem fairly thick but keep going. Gradually stir or whisk in the stock. Let the gravy simmer for 10 minutes until dark brown and thickened. Check for seasoning – it’s unlikely to need salt, but add a few drops more of balsamic vinegar and you might find the flavour rounds out even further. Serve piping hot, or let it cool and chill. Can be made up to 2 days ahead, then cover and refrigerate, or freeze.