Combine the first 2 ingredients in a small bowl to make the Seasoning Mix.
Sprinkle the turkey evenly with 1 tablespoon plus 2 teaspoon of the Seasoning Mix and rub it in well. Set aside.
In a heavy 4-quart pot over high heat, heat the oil just until it begins to smoke, about 3 to 4 minutes.
Make a roux: To the pot add the flour and whisk the mixture constantly until it is red-brown, about 6 to 8 minutes. To the roux add the onions, bell peppers, poblanos (or other mild fresh chiles), smoked sausage (optional), and the remaining Seasoning Mix. Stir well, reduce the heat to medium and cover. Cook, uncovering to stir and scrape every 2 to 3 minutes to prevent burning (as there is no liquid in the pot), for 18 minutes. Add the seasoned turkey meat and 3 cups of the stock. Stir and scrape the pot completely. Cook stirring and scraping every 1 or 2 minutes, for 8 minutes, then add the remaining stock. Reduce the heat to low and simmer until the gumbo is thick and golden, about 10 minutes. Serve over hot white rice.