Arrange the peach slices into the bottom of a large serving dish. Sprinkle over the lavender heads and add the strips of lemon rind.
Pour over enough dessert wine to cover the peaches. Turn the peach slices over a couple of times to coat them in the liquid, then cover the dish and chill the mixture in the fridge for at least four hours, or preferably overnight.
To serve, spoon a portion of peaches in Sauternes into each of six serving bowls. Serve with a dollop of crème fraîche, if using.