Finely chop 1 or 2 onion slices to make about 2 tablespoons.
In a saucepan, cook the chopped onion in 1 tbsp oil, stirring, until translucent and limp. (Reserve the remaining onion slices.)
Mix in the rice, stock, raisins, seeds, cinnamon, half of the salt and half of the pepper.
Bring to a boil over high heat, lower the heat, cover and cook until the rice is tender, about 45 minutes.
While the rice mixture is cooking, remove the core from the cabbage and discard.
Place the cabbage in a large steamer or a deep soup pot and steam until the outer leaves become limp enough to remove one by one. (You'll need at least 18 leaves, and more if possible.) Lay out the leaves on a clean dishcloth to cool.
Using a knife, remove the thick lower portion of the veins.
Finely shred the remaining cabbage and reserve.
Drain the sauerkraut, cover with fresh cold water, drain again and reserve.
In a casserole dish, cook the reserved onion slices in remaining tbsp of oil, stirring,until limp, about 3 minutes.
Add the shredded cabbage, sauerkraut, chopped tomatoes and their juices, tomato paste with water and remaining salt and pepper.
Bring the mixture to a boil, stirring constantly.
Stir in the honey or date sugar and simmer a few minutes to blend.
Taste and add more honey or date sugar if needed to balance the sour.
Remove from heat.
Preheat the oven to 350°F.
Fluff the rice mixture to distribute the raisins, sunflower seeds and spices.
Place 2 tbls.
of the filling on the lower third of a cabbage leaf.
Fold up the lower part of the leaf, then fold over both sides, and roll up.
Repeat with the remaining filling and cabbage leaves.
Place the rolls seam side down into the casserrole dish, pushing them into the sauce.
Cover and bake 25 minutes.
Spoon the sauce over the rolls and bake 20 minutes more.
If desired, continue baking, uncovered, to brown the top.