1) Peel shallots, cut them thinly sliced, put them on in a non-stick pan with butter and sauté them over a very low heat, stirring often with a wooden spoon. When they are almost transparent, salt them moderately e flavor them with a generous grind of pepper; paid the Champagne and let it reduce by half, always over low heat.

2) Open up oysters, taking care to collect their liquid in a small bowl; detached molluscs with valves without breaking them, put them in another bowl e cover them with their filtered liquid.

3) Rub well the concave shells with a stiff brush and place them on the very hot oven plate until they have heated up a little. Distribute the oysters in the hot shells and arrange them on a serving plate, making sure that they remain straight; helping you with a ladle, sprinkle them with Champagne shallot sauce e sprinkle them with a handful of finely chopped tarragon. Serve them immediately.