Prepare a pot for stewing. Heat a frying pan with a little oil, add finely chopped onions, fry until tender. Add chopped garlic. When the garlic is fried, add the canned tomatoes and remove the pot from the heat.
Dust the cabbage rolls with flour, lightly, you don't need much, and fry them in a heated pan. The leaves don't need to start browning, just a little. We want the flour to get fat and fry a little. Arrange such cabbage rolls directly in the casserole.
When you've put them all together, season with pepper, a little salt, and add enough water to cover halfway. Cover with a lid and simmer on low heat. Cabbage rolls made with fresh cabbage will cook in about half an hour. If you cook from winter, harder cabbage, sauté a little longer.
Every time you use it, check whether the liquid is missing and if it is missing, add a little. I usually simmer everything in the pressure cooker so none of the liquid evaporates.
Season with parsley at the very end. Serve on a plate with boiled potatoes or mashed potatoes. Season with sour cream.