Best Deviled Eggs

Cover eggs with cold water by 1 1/2 inches in a 3-quart heavy saucepan and bring to a rolling boil, partially covered. Reduce heat to low and cook eggs, covered completely, 30 seconds. Remove from heat and let stand, covered, 15 minutes. Transfer eggs with a slotted spoon to a bowl of ice and cold water to stop cooking and let stand 5 minutes.

Peel eggs and halve lengthwise. Carefully remove yolks and mash in a bowl with a fork. Add mayonnaise, mustard, and cayenne and stir with fork until smooth, then season with salt and pepper. Fill pastry bag with yolk mixture and pipe into egg whites.