I have a grandchild who is highly allergic to sesame. Would peanut butter work as a substitute for tahini in the Slow Roast Pork Belly recipe?
Nigella's Slow Roast Pork Belly (from KITCHEN) steeps the meaty underside of the pork belly overnight in a marinade of tahini, soy sauce and lemon and lime juice. NIgella has used peanut butter instead of tahini in another recipe, Peanut Butter Hummus, so we suspect that it would be possible to use smooth peanut butter as an alternative for the pork belly. However we would suggest that, if possible, you use a "natural" type of peanut butter that is made from just ground peanuts and not a type that contains added sugar and other oils.
You can also just omit the tahini from the marinade. This will make the marinade slightly more liquid so you may need to spoon some of the marinade over the sides of the pork belly once it is sitting in its roasting tin.