Rognons de veau à la moutarde

It’s funny how in Britain many people don’t think twice about wolfing down kidneys when they’re buried under a robust sauce and married with mouthfuls of succulent steak and buttery pastry, yet they’re suddenly less appealing when served as the hero of a dish – humble and honest, yet somehow a little awkward and unsightly. In France, we have no such squeamishness; the longevity of this dish, another brasserie stalwart, is testament to its popularity.

Good-quality kidneys should be v