Preheat oven to Fan Oven 160°C/180°C/350°F/Gas 4

Lay the peanuts out in a single layer on a large baking tray and put in the oven for 5 minutes. After 5 minutes take out of the oven and stir the peanuts. Return to the oven for a further 5 minutes and repeat for a further 5 minutes – 15 minutes in total. 

Put the peanuts into a food processor and process on high until the nuts are chopped into small chunks. If you want to make crunchy peanut butter, remove ½ - ¾ cup of nuts from the processor. If you want smooth do not remove any.

Continue to process until the nuts form a paste. You may have to stop the processor from time to time to scrape the peanuts down from the sides of the processor.

When the peanuts are a paste, add the salt and oil and continue to process until you have the texture you require.

If you are making crunchy peanut butter, stir in the reserved chopped nuts.

Divide the mixture into 2 jam jars and seal with a lid.