Combine the seasoning mix ingredients in a small bowl. Preheat a heavy 5-quart pot over high heat to 350°, about 4 minutes. Sprinkle all surfaces of the chicken evenly with 5 teaspoons of the seasoning mix and rub it in well. Place the chicken in the pot and cook, turning twice, until well browned on all sides, about 10 minutes in all. You may have to cook the chicken in batches. When the chicken is brown, remove it from the pot and set it aside. To the pot add 2 cups of the onions, 1 cup of the bell peppers, 1 cup of the mushrooms, 1 cup of the greens, the bay leaves, and the remaining seasoning mix. Cook, scraping the bottom of the pot frequently, until the vegetables begin to stick, turn brown, and seem in danger of burning, about 5 minutes. Add 1/2 cup of the stock, scrap the bottom of the pot clear, and cook, scraping occasionally, until the stock is almost absorbed, about 6 minutes. Blend in the flour and cook until it starts to brown, about 3 minutes. Add the tomatoes with their liquid and the remaining ingredients and bring to a boil. Add the chicken and any juices that have accumulated. Reduce the heat to a fast simmer and cook, covered, until done, approximately 20 minutes. Serve over rice.