Cook the pancetta in a large rondeau pot over low to medium heat until the fat is rendered. Set the crispy lardons to the side.
Pat dry the short ribs on all sides, then season with salt and pepper.
Place the short ribs into the pot, fat cap side down, and cook over medium heat and brown well on all sides, which takes about 3 to 4 minutes per side. Set them to the side.
Stir in the onions, gently season with salt, and cook for 5 minutes or until they start to turn brown. Then, turn the heat down to low and cook for 10 minutes while occasionally stirring.
Mix in the carrots and celery, add on a lid, and sweat over low heat for 10 minutes.
Add the garlic and cook just until fragrant, which takes 30 to 45 seconds.
Stir in the tomato paste and cook for 2 to 3 minutes or until it turns a rust color.
Deglaze with red wine and cook over medium heat for 5 to 7 minutes to reduce and concentrate the wine flavors.
Pour in the tomato puree, beef stock, herbs, cooked pancetta, salt, and pepper, and mix to combine.
Place in the short ribs, add on a lid and cook over low heat for 2 ½ to 3 hours or until the beef is fork tender.
Remove the herbs and bones from the short ribs in pan. Break up the beef in the sauce using two forks or a large spoon.
Garnish with optional finely minced fresh parsley.
