Hey London Jews, where do I get Challah on Friday afternoon?

I’m getting into St Pancras at around 2pm this Friday and would ideally love to pick up some challah before taking a train to London Liverpool Street (to take the overground to Chingford.

Do you know a place near st Pancras, Liverpool Street on Chingford Station? Or any place that wouldn’t involve me schlepping my suitcase across town?

Thanks in advance for your insight!