You can even use a microwave...
250g Oats - I used rolled but it's not a big deal if you don't
125ml runny honey
250g peanut butter
Put your peanut butter and honey in a bowl, pop it in the microwave for about 40-50 seconds, take it out and give it a good mix. Throw in your oats and stir well. It's quiet a heavy mixture so check the bottom of the bowl for dry oats.
Line any shaped baking tray with baking paper and tip your mixture in. Press it all down firmly until even(ish) on the top.
Chill in the fridge for an hour or two then cut into bitesized pieces. Mine don't get to the fridge, they get a half an hour on the side cool before being demolished.