Heat olive oil in a large pot over medium heat. Add the lamb chunks and brown on all sides. Remove lamb from the pot and set aside.
In the same pot, add chopped onion and garlic. Sauté until onion is translucent.
Return the lamb to the pot, then add crushed tomatoes, beef broth, oregano, thyme, salt, and pepper. Stir well to combine.
Bring the mixture to a simmer, then reduce the heat to low. Cover and cook for about 2 hours, or until the lamb is tender.
Serve the ragu over pasta or polenta, and enjoy.