In a small bowl, whisk together the rendered sauce, milk and the flour.
Combine the shredded meat with the sauce/flour mixture in the dutch oven. Cook, over medium heat, until it comes together and starts releasing from the bottom of the pan, about 5 minutes. Season with salt and pepper. Remove from the stove and let it cool to room temperature. Cover with plastic and refrigerate for one hour.
Remove the meat mixture from the refrigerator and form 2-inch logs.
In a shallow bowl, whisk two eggs. In another bowl, place the breadcrumbs and season with salt. Working with one croquette at a time, dip in the eggs and coat with breadcrumbs.
Heat 2-inches vegetable oil in a medium saucepan, until a deep-fry thermometer reads 350 degrees F. Working in batches, fry the oxtail croquettes until golden and crispy, about 2 minutes per batch, turning as needed.
Transfer the fried oxtail croquettes to a paper towel lined plate to drain.
Serve hot with lime wedges and mustard.