Preheat your oven to 350°F (175°C).
Season the lamb shanks generously with salt and pepper.
Heat olive oil in a large pot or Dutch oven over medium-high heat.
Sear the lamb shanks until golden brown on all sides, about 3-4 minutes per side.
Remove the browned lamb shanks and set them aside.
Add diced onions, carrots, celery, turnip, parsnip, and garlic to the pot.
Sauté the vegetables, stirring occasionally, until they are well-browned, about 10 minutes.
Deglaze the pot with red wine, reducing the liquid by half.
Stir in tomato paste, then add beef stock, parsley, thyme, rosemary, salt, and pepper.
Return the lamb shanks to the pot, cover, and braise in the oven for 2 to 2 1/2 hours.