1.Cut the core from the lettuce. Rinse lettuce under cold running water, with the cored end facing upwards, the whole leaves should slip off easily. Put 12 medium- sized lettuce leaves with a good `cup’ shape in a bowl of iced water and keep in the fridge until required. (Keep the rest of the lettuce in a resealable plastic bag in the fridge for another use.)
2.Put the eggs and unpeeled potatoes in a medium saucepan, add enough cold water to the pan to completely cover the eggs and potatoes. Heat the pan on the stove over high heat until the water boils. Boil for 7 minutes then remove the eggs with tongs and put them in a small bowl of cold water. When cool enough to handle, gently crack the egg shells all over, leave in the water to cool.
3.Continue boiling the potatoes until they are soft when tested with a fork or skewer. Drain the potatoes in a colander over the sink, then cool.
4.Meanwhile, tear the prosciutto into pieces. Put a medium frying pan on the stove over high heat. Add the prosciutto and cook, stirring with a wooden spoon, until the prosciutto is browned and crisp. Remove the prosciutto from the pan and drain on absorbent paper.
5.Remove the chicken meat from the bones. Shred the chicken meat into pieces.
6.Peel away the egg shells. Peel potatoes. Chop the eggs, potato and basil coarsely.
7.To make the dressing, mix the mayonnaise, sour cream, honey and mustard in a large bowl, season to taste with salt and pepper. Add the chicken, egg, potato, basil and prosciutto, mix gently.
8.To serve, spoon about ½ cup of the chicken mixture into each lettuce cup.
Trim the edges of the lettuce leaves with kitchen scissors to make them look neater. Hold lettuce, cored end up, under cold running water. The water will get between the leaves, making them slip off easily and intact.Note