Too Big For His Britches

Whatever it is you want to do: I've got a recipe that'll do exactly that. You want an exploding potion? BOOM!! You want a lightning potion? ZAP!! You want a shrinking potion? Smeerp. So Bronwyn says he wants a carbon-dating potion? Easy. I could make that in my sleep. The thing is... if we want it to be accurate, I need you to get some quality ingredients. Start with some humour from a basilisk to the north. It'll need to be a pretty big basilisk...