Toast the sesame seeds in a large frying pan, stirring constantly until they start to change colour. Toasting the sesame seeds before making the tahini gives the sauce a far superior flavour.
Transfer the toasted sesame seeds to a food processor, then blend until a crumbly paste forms. This will take about 1 minute.
Drizzle the oil a little at a time into the food processor and blend until you have a smooth, creamy paste. You may not need all the oil. Season the tahini with salt to taste. If you want a really smooth paste, you can push the tahini through a sieve with the back of a spoon before storing.
Transfer the tahini to a covered container and store in the fridge for up to 1 month.
