Preheat the oven to 400°F.
Boil cabbage leaves in salted water for 3-5 minutes, then let them loosen.
Sauté cauliflower and onion in butter, season with salt and pepper, then let cool.
Mix the sautéed veggies with heavy cream, salt, and pepper, then fill each cabbage leaf and roll.
Fry the rolls in a skillet until lightly browned on both sides.
Bake the rolls in a dish for 30 minutes, keeping the cabbage juice aside.
Simmer heavy cream, soy sauce, salt, pepper, and cabbage juice until thick, then serve with the rolls.