Heat the gnocchi for about 1 minute in boiling salted water. Grate cheese. Drain gnocchi and mix with cream and cheese. Pour into a greased casserole dish. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes.
Wash herbs, shake dry, pluck leaves from the stems and chop. Wash the meat, dab dry. If necessary, cut large fillets in half lengthwise. Season meat with salt and pepper. Peel onion and cut into rings.
Wash the tomatoes, cut them in half. Heat oil in a pan. Fry meat for 10-12 minutes, turning. Turn the meat in the herbs and wrap each one firmly in foil. Fry the onion rings in the frying fat until golden brown.
Add the tomatoes and fry briefly. Season with salt and pepper. Take the casserole out of the oven. Spread onion and tomatoes on top. Unpack meat, cut into slices and place on the casserole.