In a bowl, mix the ground meat with rice and spices.
Carefully separate the cabbage leaves, setting aside the whole ones suitable for rolling.
Chop the broken or unusable cabbage leaves and set them aside to layer at the bottom of the pot and over the stuffed rolls.
In a cast-iron pot, layer 125 ml (1/2 cup) of tomato puree, bay leaves, fresh thyme sprigs, and some chopped cabbage at the bottom.
Place a spoonful of the meat mixture in the center of a cabbage leaf, fold two opposite sides, then roll it tightly. Repeat until you have used all the filling (makes around 25-30 rolls, depending on their size).
Arrange the stuffed cabbage rolls in the pot, layering them in a circular pattern on two levels, leaving space in the center for the smoked pork hock.
Cut the smoked pork hock into pieces and place them in the middle of the rolls.
Top with chopped cabbage, pour over the remaining tomato puree, sprinkle in the peppercorns and a few fresh thyme leaves, then add enough water to fully submerge the rolls.
Cover the pot with a lid and bake in a preheated oven at 200°C/390°F for 2 hours. Check occasionally to make sure the liquid doesn’t evaporate completely—though usually, no extra water is needed.
Serve the hot stuffed cabbage rolls with sour cream and fresh thyme leaves. They are absolutely delicious!