Red mullet, leeks and bone marrow-stuffed potatoes

By Amandine Chaignot From Saturday Kitchen Ingredients 500g/1lb 2oz baby potatoes 4 bone marrow bones, cut into 5cm/2in length 1 bunch fresh chives 1 tsp vegetable oil 100g/3½oz butter 1 shallot, finely chopped 1 bunch thyme 1 head garlic 4 red mullet, prepped, setting aside bones and …