Crawfish Stew

* 1/ 2 cup cup canola oil * 1/2 cup all-purpose flour * 3 1/2 pounds yellow onions, finely diced * 1/2 cup finely diced green bell pepper * 1/2 cup finely diced celery * 1 bay leaf * 4 pounds crawfish tails, with fat * 1/2 teaspoon cracked black pepper, plus more as needed * 1/2 teaspoon cayenne pepper, plus more as needed * 1 tablespoon hot sauce, preferably Original Louisiana Hot Sauce, plus mor…