Base Curry Sauce

This is one of the base curry recipes used by Dan Toombs, The Curry Guy. If you cook lots of curries, make up a batch of this and store what you don't use in the freezer. On it's own, this is actually a bland-tasting liquid, but it adds terrific depth to finished curries. Because it can be used in something as mild as a korma or as ferocious as a phal, it doesn't contain any real chilli heat.

Peel and dice the onion. Dice the bell pepper. In a medium saucepan or pot over medium-high heat, make the oil hot and throw in the onions and bell pepper. Cook them until soft but not browned. Stir in the remaining ingredients except the water. Fry for about 30 seconds, add 250ml (1 cup) of water, and cook for 5-10 minutes until half of the water has evaporated. Now add another cup of water and blend the mixture using an immersion blender (stick blender) or a tabletop one. Try to get a really smooth mixture. Add the remaining water. You'll probably have a lot more sauce than you need - typically, recipes use 250ml or 500ml (1 or 2 cups), so freeze the remaining sauce in containers of those sizes.