You may already be in the habit of putting a piece of activated charcoal, called binchotan, into a jug or bottle to purify water. But did you know that you can also use it to gently grill your summer dishes without producing any smoke or smells? At the beginning of spring, the Michelin-starred chef Jacky Ribault’s Les Mérovingiens restaurant — in Noisy le Grand, just outside Paris — started serving a perplexingly titled dish, promising a foie gras escalope ‘au binchotan.’ Arnaud Baptiste, the chef helming the kitchen of this establishment, popular with the Parisian foodie community, has opte…