Combine the flour, baking powder, sea salt and sugar in a bowl. Beat the buttermilk, oil, egg and 100ml water together, then mix the wet ingredients into the dry.
On a dusted surface, roll the dough out to 1cm thick.
Peel and finely dice the shallot.
Bake on a dusted baking tray for 15 minutes, then remove and top with the chopped shallot and the remaining ingredients. Serve with a good pinch of pepper, and the lemon wedge on the side for squeezing over.