Butter an 18cm souffle dish, or 4 one-cup souffle dishes. Cut a doubled sheet of greaseproof paper long enough to wrap around dish and overlap by 8cm. It should be deep enough to extend 5cm above the rim. Butter the paper and tie firmly with string just under the rim of the dish. Place a baking tray on a shelf in the centre of the oven and set the oven to hot 200C (400F). Melt the butter, stir in the flour and cook over low heat for 1 minute. Remove from heat, cool a little, and blend in milk, stirring until smooth. Return to heat and stir until boiling, then take from heat and stir in the cheese and seasonings. Beat in the egg yolks, one at a time. Whisk the egg whites with cream of tartar until firm but not brittle and fold into cheese mixture. Pour the mixture into the prepared dish or dishes, tap the bottom of the dish lightly on the work surface to expel any large air pockets, and smooth the top of the souffle. Quickly run a spoon around the top of the mixture about 2.5cm from the edge to make the souffle rise evenly in a 'crown'. Immediately place the souffle dish on the baking tray in the centre of the oven, close the door gently, and turn the oven down to moderately hot 190C (375F). Do not open the oven door for the next 15 minutes. Bake the souffle until it is Right: Sure to become favorites with guests are Mushrooms With Fresh Herbs, Cheese Souffles and Watercress And Violet Salad. well puffed up, golden brown on top and just firm, about 24 minutes (18 minutes for individual souffles). Have a heated serving platter (or plates) ready and a warmed serving spoon and fork. Place the souffle dish on the platter, remove the paper and take immediately to the table. To serve, pierce the top lightly with the spoon and fork held vertically, and spread the souffle apart. Include some of the outside crust and some of the creamy centre with each serving. Serves 4-5.