tl;dr

Rupert recommended this recipe to me, so I’m putting it on my “todo”.

Put the butter (large knob), 2 glugs of olive oil, the sage (handful) and garlic (6 cloves, peeled, crushed) into a thick-bottomed, non-stick pan. Stir everything round and add the onions (5 red, 3 large white), shallots (3 banana) and leeks (300g). Season with salt and pepper. Place a lid on the pan, leaving it slightly ajar, and cook slowly for 50 minutes, without colouring the vegetables too much. Remove the lid for the last 20 minutes – your onions will become soft and golden. Stir occasionally so that nothing catches on the bottom.

When your onions and leeks are lovely and silky, add the stock (2 litres, beef/chicken/veg). Bring to the boil, turn the heat down and simmer for 10 to 15 minutes. You can skim any fat off the surface if you like, but I prefer to leave it because it adds good flavour.

There’s some optional mucking about with cheese on toast in the original recipe that I have omitted here for brevity.

Food