The Gratin de Cardons à la Moelle is Lyon’s traditional Christmas dish—a gratin of cardoon stalks (cardon, a thistle-family vegetable related to the artichoke) with bone marrow, Béchamel, and Gruyère—a preparation that appears on virtually every Lyonnais table on December 25th. The cardoon (Cynara cardunculus) is a vegetable almost extinct outside Lyon, southeastern France, and parts of Italy and Spain: it resembles giant celery but tastes like a milder, more elegant artichoke heart, with a gentle bitterness and a mineral, vegetal depth. The preparation is laborious: the tough outer fibres must be peeled from each stalk (using a paring knife to strip the strings, as with celery), the prepared stalks are rubbed with lemon juice to prevent oxidation, then blanched in acidulated blanc (water with flour and lemon juice) for 30-45 minutes until tender. The blanched stalks are cut into 5cm lengths and arranged in a buttered gratin dish. Over this, poached marrow bones are carefully cracked and the quivering discs of marrow (poached at 80°C for 10 minutes until just yielding) are arranged. A Béchamel sauce enriched with 50g of Gruyère is poured over, more Gruyère is scattered on top, and the gratin is baked at 200°C for 20-25 minutes until bubbling and deeply golden. The combination is extraordinary: the cardoon’s gentle bitterness, the marrow’s unctuous richness, and the gratin’s golden crust create one of French cuisine’s most satisfying winter dishes.
Peel the cardoon stalks thoroughly—the tough outer fibres are inedible and unpleasant. Blanch in acidulated blanc to prevent oxidation and to tenderise. Poach the marrow at exactly 80°C—higher and it melts away, lower and it remains waxy. Layer cardoons and marrow before topping with Béchamel and cheese. Bake at high heat (200°C) for a quick, golden gratin crust.
Start preparing the day before Christmas: blanch and cool the cardoons, poach and slice the marrow, make the Béchamel, and assemble the gratin ready for baking—on Christmas morning, it goes straight into the oven. Add a grating of truffle over the Béchamel before the final layer of cheese for an elevated version that is pure Lyonnais luxury. If fresh cardoons are unavailable (they appear in markets from November to February), tinned cardoons from Spanish or Italian producers are an acceptable substitute—drain and rinse well before using.
Not peeling the stalks sufficiently, leaving tough, stringy fibres in the gratin. Blanching in plain water without the flour-and-lemon blanc, which causes the cardoons to oxidise and turn grey. Overcooking the marrow until it dissolves into the sauce rather than remaining as distinct, melting discs. Making the Béchamel too thick, which produces a stodgy rather than flowing gratin. Substituting artichoke hearts, which while related, have a completely different texture and lack the cardoon’s characteristic bitterness.
La Cuisine Lyonnaise — Félix Benoit