Gratin de blette

• 3 lb (1.5 kg) Swiss chard, white ribs only
• 2 oz (

Blanch the chard in boiling salted water for 30 minutes.

Make a white sauce with the rest of the ingredients. Arrange the drained chard in an ovenproof dish and cover with the white sauce and a thick layer of cheese. Pop in a hot oven, gas mark 6, 400°F (200°C), until brown and bubbling, or put under the grill.