Vegetarian Stuffed Cabbage

Yield: 12 Cabbage ro
1tbExtra-virgin olive oil
1lgOnion, peeled and chopped fine
1lgShallot, peeled and chopped fine
1lbMushrooms, cleaned, trimmed, and sliced
2Carrots, peeled and grated
1smRutabaga (yellow turnip), peeled and grated (about 1 cup)
2pk(10-ounce) frozen chopped spinach, thawed and squeezed dry
2Zucchini, trimmed and diced
1 1/2cCooked brown rice, barley, or kasha
2tsSalt-free vegetable seasoning
Freshly ground pepper
1/2cChopped Italian flat-leaf parsley
12lgSavoy cabbage leaves
3cShredded savoy cabbage
2cVegetable broth
6Fresh ripe or canned plum tomatoes, cored and diced
2tsExtra-virgin olive oil
1/3cNonfat plain yogurt or nonfat sour cream
3tbChopped fresh dill or chives, for garnish