Finally able to tick something of my 'to do' list. Not difficult at all. 
I bought peanuts roasted in their shells. I didn't have to roast them, but peal them... 200 grams of peanuts, 3 tbs neutral oil and then mix until it's creamy. I choose to mix it so it hasn't got much crunch. I also choose not to add salt or sugar. I wanted a neutral peanut butter.