1) Line the bottom of a trifle bowl with biscuits, cut to fit. Pour over liqueur.
2) Chop two of the peaches and spoon them into the middle of the dish. Slice the rest of the peaches, and one of the nectarines and arrange them around the inside of the dish, so that the skin shows outwards through the glass.
3) This is cheat's custard. Make up the instant custard with half the quantity of water stated on the packet. Allow it to cool, then stir in the double cream. Carefully pour the custard over the peaches in the dish. Leave to cool completely and set in the fridge. Meanwhile, whip the cream, reserving a little for piping.
4) Spoon the cream on top and smooth over. Pipe 5 swirls around the edge of the dish. Slice the remaining nectarine and place a slice of nectarine on to each swirl.
