Remove the ribs. Keep the leaves which can be used for other tasty dishes. Skin the ribs by removing the fibres lengthways. Cut into 2 1/3- to 2 3/4-inch long sections. Blanch in a lot of boiling salted water with the juice of 1 lemon. When tender, drain, cut lengthways into fine sticks; the ribs cut this way make a more delicate gratin. Spread 1/3 of the chard sticks in a generously buttered gratin dish, sprinkle with a good tablespoon of grated cheese and 1 tablespoon of parsley, pepper, add a dash of nutmeg. Put a second layer of chard, cheese, parsley, and finish up with the remaining chard moistened with a beaten egg yolk and cream mixture. Sprinkle with cheese, top with the remaining butter. Gratin in a hot oven (400F).
