Remove the core from the cabbage. Bring a large pot of salted water to a boil. Cover and cook cabbage for 8 to 10 minutes. Place in cold water. Peel 12 leaves for the rolls, cutting the thick vein from the leaves as necessary. Drain on towels.

Preheat oven to 375 degrees.

Meanwhile, spray a medium saucepan with olive oil. Add onion and pepper and cook for 10 to 12 minutes, until tender. Add quinoa, garlic and tomato paste and sauté for 2 minutes. Add vegetable broth, parsley, thyme, salt and pepper. Bring to a simmer and reduce heat to low. Cover and cook for 30 to 35 minutes. Stir in zucchini and Parmesan cheese and re-cover. Allow to sit off the heat for 5 minutes. Cool slightly and stir in egg if desired. (You want to make sure the mixture has cooled enough to not cook your egg.)

Divide quinoa mixture among the prepared cabbage leaves. Roll up leaves to enclose the filling. Place seam side down in a casserole pan. Top with tomato sauce.

Bake for 30 to 35 minutes. Allow to sit for 10 minutes and serve.