Where to find the best hot chocolate in London

I’ve a confession to make. All women are supposed to be addicted to chocolate but I’m not one of them. I can actually be in the same room as a box of chocolates and not dip into them - or not if they’re run-of-the-mill chocolates anyway. It’s not that I don’t like them. I enjoy an occasional square of dark chocolate after dinner but that’s as far as it goes. Weird, I know.