1 Large Savoy cabbage,it looks like the regular cabbage only it is krinkly...remove 2 outer leaves and set them aside to put on the bottom of the roasting.
Cut out the core of the cabbage about an inch deep. boil a pot of water and put in the cabbage, core side down..just simmer..when the leaves are cooked they will be soft and easy to roll. remove from pot onto plate or cutting board and cut the soft leasves at the cord..return cabbage to pot and steam the same until you have all the leaves off, cool the leaves and hold the leaf in your hand or placed on board and trim off to same level as leaf, the hard ridge on back of leaf. set aside and make your stuffing.
In large bowl add the ground pork, chicken and mix with clean hands until well combined.add the egg, onions,garlic,half the mushroom which has been finely chopped [keep threst for gravy only sliced|,,add the seasonings and 2 tables of the onion soup mix, combine these all together...now comes making the rolls.
Place the leaf on the cutting boar or hold it in your hand with outer leaf on the bottom. fill with about half a cup of filling,with the wide edge , fold over the filling, then fold over each side of the leaf and roll the leaf til filling is enclosed..place the rolled cabbage with the under side of the leaf which rolled is on the bottom continue making all the rolls...if you have meat filling left over make meat balls, hamburger patties or small meat loaves.
M ix the remaining onion soup mix with the stock and pour over the cabbage roll along with the sliced mushrooms. Cover and bake in 350F oven for 1 hour and 15 minutes..remove one and test to see if filling is cooked and leaves are very soft. Remove with pan with slotted spoon and set aside..thicken the stock with your method of thickening the gravy,,,add the onion soup and mushrooms and cook until the gravy is done, return the cabbage rolls back to the pan, keep warm in oven at 250F until ready to serve with your yummy mashed potatoes.....You can make the filling the way you make your meat balls and meat loaf,
This seems like a lot of work but is well worth the effort..I sometimes make the filling and soften the cabbage leaves the day before keep them in the fridge until you are ready to roll....just a pun,,,haha.