Soak rolls in water. Clean the savoy cabbage, separate the leaves one by one and cut out the stalk. Cook in boiling water for about 5 minutes. Take out and let drain. Peel onion and garlic and chop finely.
Squeeze the bread roll well and knead it together with the minced meat, egg, onion and garlic. Wash the thyme, dab dry and chop finely. Add to the minced meat and knead. Season with salt and pepper. Line an oven dish (approx. 2 litres capacity) with bacon.
Allow to protrude slightly at the edge. Leave 6-7 slices for covering. Place a layer of savoy cabbage leaves on the bacon. Season with salt and pepper. Spread half of the minced meat mixture on top and cover with another layer of savoy cabbage leaves.
Season again. Spread the remaining minced meat mixture on top and finish with another layer of savoy cabbage. Cover with the remaining bacon and fold over the protruding edge slightly. Cover with aluminium foil and cook in the preheated oven (electric range: 150 °C/ gas: level 1) for about 1 1/2 hours.
After approx. 1 hour remove foil, pour cream over it and continue cooking open. 15 minutes before the end of the cooking time, turn the oven up to 200 ° C (gas: level 3) and bake. Serve garnished with thyme as desired.