Carbonade is a Flemish and northern French stew of beef and onions slow-cooked in beer, the Belgian classic being carbonade flamande. Chunks of braising beef simmer for hours with sliced onions, brown sugar or syrup, mustard-spread bread, and a dark abbey-style beer, producing a sweet-savoury sauce with malty depth. The long braise converts tough collagen to gelatin while the beer’s bitterness balances the onions’ sweetness. It is traditionally served with chips or boiled potatoes. Like all slow braises, it improves with resting and reheating, and it showcases how beer functions as both cooking liquid and flavouring.