Wipe endives with a damp paper towel. With a pointed knife, remove the hard part from the base of the leaves by hollowing out the center. Melt 2 Tbsp butter in a non-stick frying pan. Add the endives, sprinkle with sugar, salt and pepper to taste. Cook about 40 minutes over medium-low heat (the endives should be lightly browned and soft). Meanwhile, melt 1 Tbsp butter in a saucepan. Add the flour and cook one minute, stirring constantly. Gradually add the milk and continue to stir. Cook until thickened. Add the whipping cream, 1/3 cup grated cheese, a pinch of nutmeg and salt and pepper to taste. Leave to cook another 5 minutes, stirring continuously. Preheat the oven to 425ºF. Lay the slices of ham flat; sprinkle them with 1/3 cup grated cheese; top each slice with an endive, roll them up and arrange the rolls in a buttered ovenproof dish. Cover them with the sauce and sprinkle them with the remaining 1/3 cup of gruyère. Bake for about 30 minutes. Serve hot in the cooking dish.

Serves 6