Preheat the grill to high. Lay the slices of bread slightly overlapping in a shallow flameproof dish. Sprinkle about 2 tbsp of the sugar in an even layer over the bread and grill for about two minutes until the bread is toasted and the sugar is just starting to caramelise. Mix the cornflour into the lactose free double cream.
Pile the fruit down the middle of the bread and sprinkle with 1 tbsp of the sugar. Drop spoonfuls of the lactose free double cream mixture on top, then sprinkle the rest of the sugar over evenly.
Put the dish as close to the heat as you can and grill for about 6-8 minutes, until the lactose free double cream has browned and everything else is starting to bubble and turn juicy. Leave it to sit for a minute or two, then serve hot, spooned straight from the dish.