Heat a very big, heavy-bottomed pot over high heat, then reduce the heat to medium. (This lets the pot heat uniformly, preventing hot spots that are likely to burn.) Brown the andouille and pork sausage in the bacon fat, stirring slowly with a long wooden spoon to build color. While the sausage is browning, season the chicken thighs with salt and pepper. Add the chicken to the pot (the dark meat is so flavorful!), stir, and cook until the chicken turns golden brown, about 5 minutes.
Once the chicken has browned, add the onions and let them caramelize for about 15 minutes to build more flavor. I add the bell peppers late, to save as much of the color as I can. Add the celery (I always use the leaves, too) and garlic and cook for about 5 minutes, stirring occasionally so that everything cooks evenly.
Next add the rice, pimenton, cayenne, thyme, bay leaf, 1 tablespoon salt, and ½ tablespoon pepper to the pot and cook, stirring often, for about 3 minutes. Increase the heat to high and add the tomatoes, stock, Tabasco, and Worcestershire. Bring the liquid to a boil, then reduce the heat to medium low, cover, and simmer for 15 minutes.
Fold in the green onions. Cover again, turn off the heat, and let the rice steam in the hot pot for another 10 minutes. Fluff the jambalaya with a fork and serve!