Bring a large pot of water to boil. Carefully separate the cabbage leaves and blanch them in boiling water for about 2-3 minutes until they are pliable. Drain and set aside.
Make the Filling:
In a large skillet, cook the ground turkey or chicken over medium heat until browned. Add onions and garlic, cooking until softened.
Stir in diced tomatoes, tomato sauce, oregano, basil, salt, and pepper. Cook for an additional 5-7 minutes.
Add the cooked quinoa or brown rice to the meat mixture. Stir until well combined. Remove from heat.
Assemble the Cabbage Rolls:
Place a cabbage leaf on a flat surface. Spoon a portion of the meat and rice mixture onto the center of the leaf. Roll the cabbage leaf, tucking in the sides, to form a tight roll. Repeat with the remaining leaves and filling.
Prepare the Sauce:
In a bowl, mix crushed tomatoes, tomato paste, dried thyme, salt, and pepper. Adjust seasoning to taste.
Bake:
Pour a small amount of the tomato sauce into the bottom of a baking dish. Arrange the cabbage rolls in the dish and cover with the remaining tomato sauce.
Cover the dish with foil and bake for 40-45 minutes, or until the cabbage rolls are tender.
Serve:
Allow the cabbage rolls to cool for a few minutes before serving. Optionally, garnish with fresh herbs like parsley.