Lyonnais cardons à la moelle gratin with beef marrow
Cardons à la moelle are not simply cardoons under a cheese crust. The Lyonnais identity comes from pairing the slightly bitter, artichoke-like vegetable with beef marrow, whose richness changes both flavour and nutrition. Fresh cardoon also demands more preparation than an ordinary gratin vegetable: the ribs need their tough strings removed and must be protected from browning while they are trimmed.
Work through the cardoon stalks methodically, stripping fibres and dropping each cut piece into lemon-acidulated water. The ribs then simmer until a knife slides through the thickest piece with little resistance. That tenderness must be achieved before the gratin is assembled; thirty-five minutes in the oven is for heating, melding and browning, not for rescuing raw fibrous cardoon.
Use commercially cut marrow bones rather than attempting to saw bones at home. Simmer the bones gently in a separate saucepan, remove about 120 g cooked marrow and distribute it in small pieces through the cardoons. A pale butter-and-flour velouté binds the dish, with grated cheese and breadcrumbs providing the top crust. Because marrow is exceptionally energy-dense, it is counted explicitly in both portion size and nutrition instead of being treated as a negligible garnish.
