Traditional Holubtsi require patience in preparing the cabbage leaves. The whole head of cabbage is boiled in salted water to loosen and soften the leaves for rolling.
The filling is a combination of ground meat and rice, which absorbs the flavour of the tomato sauce during the slow simmering process. They are always served with sour cream.
Core the cabbage. Place the whole head into a large pot of boiling salted water. Boil for about 10 minutes until the outer leaves loosen.
Carefully peel off 12-16 leaves. Cut away part of the thick ribs of the leaves to make them easier to roll. Finely chop the remaining cabbage and place it on the bottom of the braising pot (it protects the rolls from scorching).
Parboil the rice (cook until half-soft, not fully!). Drain it.
Sauté the chopped onion in oil until golden in a pan. In a bowl, mix the ground meat, parboiled rice, sautéed onion, salt, pepper, and paprika. Mix well by hand.
Place about a tablespoon (or more, depending on the leaf size) of the meat filling onto each prepared cabbage leaf.
Fold the side edges of the leaf inwards and roll the leaf from the thicker end towards the tip, forming a tight roll.
Arrange the rolls (Holubtsi) tightly next to each other in the pot on top of the chopped cabbage layer, seam-side down.
In a bowl, mix the tomato puree, broth, and sugar, season with salt and pepper. Pour the sauce over the rolls so they are submerged. Add the bay leaf.
Bring to a boil, then reduce the heat and simmer covered over low heat for 75 to 90 minutes until the cabbage and filling are completely tender.
Serve hot, drizzled with the sauce from the pot and topped with a large spoon of sour cream and sprinkled with dill.