Wash the meat, dab dry and season with salt. Heat the oil in a pan and fry for about 5 minutes, turning the meat. Wash and halve the tomatoes. For the sauce, bring cream and processed cheese to the boil.
Wash the chervil, shake dry, pluck the leaves from the stems and chop finely, except for something to garnish. Season sauce with salt and pepper. Stir in half the chervil. Cut off bread crust.
Roughly grate the bread. Melt butter. Stir in breadcrumbs and remaining chervil. Put meat and tomatoes into a greased baking dish, pour sauce over it. Spread the crust on the meat. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes.
Cut herb butter into 8 slices. Approx. 5 minutes before the end of the frying time, spread herb butter on the chicken crust. Garnish with chervil.