Preheat the oven to 350°F (175°C).
Heat the vegetable oil in a Dutch oven or large oven-safe pot over medium-high heat.
Add the pork shanks to the pot and cook until browned on all sides, about 10 minutes. Remove the pork shanks from the pot and set them aside.
In the same pot, add the chopped onion and minced garlic. Sauté until softened, about 5 minutes.
Add the pot’s beef broth, red wine, tomato paste, dried thyme, bay leaf, salt, and pepper. Stir to combine all the ingredients.
Return the pork shanks to the pot and bring the liquid to a boil.
Cover the pot with a lid and transfer it to the preheated oven. Bake for approximately 2 hours or until the pork shanks tender and fall off the bone.
Once cooked, remove the pot from the oven and use tongs or a slotted spoon to transfer the pork shanks to a serving platter.
Skim any excess fat from the surface of the cooking liquid and discard the bay leaf.
Spoon the cooking liquid over the pork shanks before serving.