Preheat the oven to 325 degrees Fahrenheit.

In a Dutch oven, heat some oil over medium to medium-high heat (or other large, oven-proof pot). Sprinkle salt on all sides of the beef and sear in batches until browned; set aside. (As you go through the batches of meat, you may need to add more oil.)

Add the onion to the same pot that you seared the meat in (with more oil if necessary), season with salt, and cook until the onion begins to soften, 1 to 2 minutes. Cook for 1 to 2 minutes more after adding the garlic cloves, tomato paste, thyme, and pepper. Deglaze the pan with the red wine, scraping up the bits on the bottom with a wooden spoon.

Add the reserved beef neck bones and beef stock to the pot, bring to a simmer, cover, and bake for 2 hours 30 minutes, or until fork tender.