Heat oven to 200C/180C fan/gas 6. Tip the peanuts onto a large baking tray, place in the oven and roast for 10 mins, stirring now and then to ensure they don’t catch at the edges. When golden brown, remove from the oven and leave to cool completely.
Tip the nuts into a food processor, and add the salt. Blend for 4-5 mins, until you’re left with a smooth nut butter, if you want to loosen the consistency, add a drizzle of oil and blend again.