Halve the chicory lengthways.
Simmer gently in salted water with lemon juice for approx. 5 mins. until soft, remove and drain.
Drain the tomatoes, peel and halve the garlic, add to the cream and bring to the boil in the same pan. Purée until smooth in a measuring jug. Finely chop the chervil, add it and the cheese to the mixture, season.
Arrange the chicory close together in a wide, greased ovenproof dish (approx. 2 litres), pour the sauce over the top.
Gratinate for approx. 15 mins. in the middle of an oven preheated to 220°C.