A cold bottle of Riesling, a sunny afternoon and a few friends should be the three ingredients required for this tart, because that’s how I prefer to eat it. But before you open the wine, you’ll just need to pick up some asparagus, puff pastry and cheese. For this is the most accommodating of tarts. It requires very little to turn simple ingredients into a dish that looks like you trained in a French patisserie to make.
