Mince the onion.

Heat butter in a pan, sauté the onion until soft, then cool.

Boil cabbage leaves briefly, cool in water, and flatten the stem with a rolling pin.

Mix milk and breadcrumbs in a bowl, add remaining meat mixture ingredients, and divide into 4 portions.

Place meat mixture on cabbage leaves, roll tightly, then wrap with bacon slices.

Place rolls seam-side down in a pot, add consomme, bay leaf, and water, then simmer for 20 minutes.