Wash the potatoes and cook in boiling water for about 20 minutes. Quench cold, peel and slice. Drain tomatoes on a sieve and cut into pieces. Wash the meat, dab dry and cut into cubes.
Heat the oil in a pan and fry the meat well all around. Season with salt and pepper. Deglaze with chicken soup and cream. Stir in the contents of the bag and bring to the boil.
Fold in the tomatoes. Grease a casserole dish (approx. 1.2 litres capacity) and layer the potato slices on the edge and season with salt and pepper. Fill the onion-cream-chicken ragout in the middle.
Cut the cheese into slices and spread on the casserole. Bake in the preheated oven (electric: 200 °C/ gas: level 3) for approx. 20 minutes. Sprinkle with chopped parsley as desired and serve garnished with basil.