Heat butter in a large pan, add the shallots and cook over a low heat for 5 minutes until softened, and slightly caramelized. Scrape the vanilla seeds from the pod and add the seeds and pod along with the garlic and artichokes to the pan, cook for a further 8 minutes. Add the potato, chicken stock and bring to the boil. Reduce to a simmer, season with salt and pepper and cook until artichokes are tender for approximately 20-30 minutes.
Remove from heat, remove vanilla pod and blend the soup until smooth. Pass soup through a fine sieve into a clean pan, add the cream and season to taste before warming through. Add a little extra stock/water if its a little too thick.
Meanwhile, pre-heat a frying pan, heat a little of the olive oil, once hot add half the butter, the artichoke wedges, vanilla salt and pepper and cook, turning occasionally, until golden and tender (4-5 minutes), remove with a slotted spoon, drain on absorbent paper.
Wipe out the pan and return to heat, once hot add the oil. Season scallops with vanilla salt and sear in hot oil over a high heat for 30 seconds on each side or until golden. Add remaining butter and cook for a minute more.
Place scallops and artichokes on the base of a large flat soup bowl, pour soup around and serve immediately.