1. Start by making the sauce for the cabbage rolls. Heat the vegetable broth for the sauce in a medium saucepan over medium heat. Add the onion, garlic, and a pinch of sea salt. Cook, stirring occasionally, until the onion is soft, around five to 10 minutes.
2. Add the remaining ingredients for the sauce, lower the heat to low, and cover with a lid. Continue cooking, stirring occasionally, until the sauce thickens up slightly, around 20 minutes.
3. While the sauce is simmering away, work on the filling for the cabbage rolls. In a large skillet, heat the vegetable broth for the filling over medium heat. Add the onion, garlic, and a pinch of sea salt. Cook, stirring occasionally, until the onion is soft, around five to 10 minutes.
4. Stir in the tempeh and soy sauce, and cook for 15 minutes, adding more broth if needed to prevent sticking.
5. Add the pine nuts, currants, caraway seeds, and pearled barley. Mix well and season with sea salt and pepper to taste. Remove from heat and set aside.
6. Preheat the oven to 350 degrees Fahrenheit.
7. Next, work on the cabbage leaves. Carefully drop one head of cabbage into a large pot with boiling water.
8. After five minutes, remove the cabbage with tongs or a large slotted spoon, and place in a colander in the sink or over a large bowl to cool.
9. When cool enough to handle, carefully remove the outer leaves. You will need 16 leaves, so you can repeat this process and boil the same head of cabbage again to be able to remove more leaves, or you can boil the second head of cabbage if necessary.
10. To assemble the cabbage rolls, place a cooked cabbage leaf on a plate and put a generous scoop of the tempeh-barley mixture on top, in the center of the leaf. Roll up the leaf over the filling starting from the bottom, then fold in each side, and lastly the top, tucking the seam underneath.
11. Repeat with the remaining leaves until you have 16 nicely filled cabbage rolls.
12. To bake the stuffed cabbage rolls, lightly oil the casserole dish and pour enough sauce to cover the bottom of the dish.
13. Place the stuffed cabbage rolls on top of the sauce and cover with the remaining sauce. Wrap the casserole dish with a sheet of parchment paper and then with a sheet of aluminum foil. Bake for one hour.
14. After one hour, check the cabbage rolls and add a little water if they have started to dry out. Bake for another 15 minutes, until they are tender when pierced.
15. Serve family style at the table, hot or at room temperature. Enjoy!