Fill a large stock pot with water to cover the cabbage. Do not add the cabbage yet. Cover and bring to a boil.
Add the head of cabbage, turn down heat and simmer for about 10 minutes. The cabbage tries to float so bob it down and turn it a couple of times while cooking.
When done life out of the water with a large slotted spoon. Set aside and start to carefully peel off the cabbage leaves. Cutting the attached end from the core. The outer one or two leaves might tear. Pull off 5 big perfect leaves. There will be some cabbage left over. Set aside and let cool for stuffing.
Cook lentils in vegetable broth. set aside.
Cook rice and set aside.
Add a couple of tablespoons water to a large skillet. Heat and add the chopped mushrooms. Cook for 10 minutes.
Add the diced onion and cook 10 more minutes.
Add paprika, cumin, garlic powder, salt and pepper. Mix and heat through.
Add the cooked lentils and rice. Mix well and heat through. Set aside.
Make the Sauce
To a large saucepan add all of the sauce ingredients. Bring to a boil and then turn down the heat to simmer and simmer for 15 minutes.
Stuff the Leaves
Spoon some sauce into the bottom of the casserole dish. I used about a 7" wide x 10" long casserole dish.
Lay a cabbage leave out and you will see how it naturally curves up. Place soe of the filling at the base of the leaf. Roll one round and then tuck in the sides and continue rolling. Place in the casserole dish. Continue until all the rolls are done.
Pour the remaining red sauce down the center of the rolls.