Roast almonds in oven at 170 degrees C for 10 minutes, then leave to cool
Add to food processor and blitz. Keep going for around 15 minutes, giving your food processor a break every few minutes and scraping the nuts back down into the bowl. It's fine to leave the nuts part-done and return an hour or so later if you become bored of watching them turn around.
Continue until your nut butter is smooth, soft, a little liquidy and drips off a spoon
Spoon into a clean, sterilised glass jar and store in the fridge for up to a few weeks.