Whisk together the ingredients for the rub in a small bowl.
Place the chicken pieces in a large bowl, and add the rub mixture. Use your hands to evenly coat, and set aside.
Heat the oil in a large pot, or Dutch oven, over medium-high heat until it begins to smoke a little.
Meanwhile, toss the chicken with the flour to coat.
Shaking off the excess flour from the chicken, transfer the pieces to the hot oil and fry until golden brown on all sides. Do this in two batches, so you don't overcrowd the pan - the chicken should be in one layer, and not on top of each other.
Reserve the leftover flour (you need about 1/4 cup...add more flour if needed).
Use a slotted spoon to transfer the chicken to a platter, leaving the oil in the pan (you should have 1/4 cup...add more if needed).
Add the remaining flour to the oil, and cook, stirring constantly, for about 5 minutes to create a medium-brown, peanut butter-colored roux.
Add the onion, celery, poblano, and garlic, and cook for another 5 minutes.
Add the chicken, tomatoes, stock, thyme, bay leaves, and hot sauce.
Simmer over low heat for 45 minutes, stirring occasionally, until thickened to a light gravy and the chicken is very tender.
Taste and adjust seasonings.
Serve over Perfectly Steamed Rice with chopped scallions as garnish (recipe below)