Put the chopped onions in a saucepan with the oil, salt, garlic and chilli if using.
Saute until the onion is transparent. This brings out the flavour of the onion
Add the paprika, red lentils and water.
Simmer for 15-20 minutes until the lentils are dissolving. Add the vinegar, any cheap one will do, and whizz until smooth. Season with salt and black pepper
Add the vinegar, any cheap one will do, and whizz until smooth.
Notes
I haven’t tried it, but you could probably use malt vinegar here, just try a tiny bit at first, a tsp, don’t want to ruin the soup. The soup is fine without the vinegar, but it does definitely bring another layer of flavour.If you don’t have any paprika, don’t worry, you won’t notice it that much.I have priced the lentils at the 500g bag level, if you can afford to get bigger bags from Indian suppliers, or some supermarkets (Morrisons seems to have them) they are half the priceI have said to use hot water in the recipe. This is not because it makes any difference to the recipe, it doesn’t, it is just because it is cheaper to boil the water in the kettle than on the stove top.You can of course make this in a slow cooker.