Put the butter, 2 glugs of olive oil, the sage and garlic into a
thick-bottomed, non-stick pan. Stir everything round and add the
onions, shallots and leeks. 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. Having the patience to cook the
onions slowly, slowly, gives you an incredible sweetness and an awesome
flavour, so don’t be tempted to speed this bit up.
When your onions and leeks are lovely and silky, add the stock. 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.
Preheat the oven or grill to maximum. Toast your bread on both sides.
Correct the seasoning of the soup. When it’s perfect, ladle it into
individual heatproof serving bowls and place them on a baking tray.
Tear toasted bread over each bowl to fit it like a lid. Feel free to
push and dunk the bread into the soup a bit. Sprinkle with some grated
Cheddar and drizzle over a little Worcestershire sauce.
Dress your reserved sage leaves with some olive oil and place one on
top of each slice of bread. Put the baking tray into the preheated oven
or under the grill to melt the cheese until bubbling and golden. Keep
an eye on it and make sure it doesn’t burn! When the cheese is
bubbling, very carefully lift out the tray and carry it to the table.
Enjoy.