Season shanks with salt, pepper, and oil, brown on a sheet pan in the oven on both sides, or in a pan over med-high heat.
Remove shanks and place in a roasting pan large enough to accommodate all ingredients.
On the same sheet pan, add a couple more tablespoons of olive oil, then add celery, carrot and onion cooking until they begin to brown.
Add garlic, cook until fragrant, about 1 minute.
Add tomato paste, cook 1 minute.
Add 2 cups of the red wine to deglaze the sheet pan, scraping loose any browned bits.
Pour the mix into the roasting pan.
Add the remaining red wine, stock, thyme and bay leaf to the roasting pan.
Cover tightly with foil and bake 325℉, for 2½ to 3 hours, or until fork tender.
Cool shanks in liquid and refrigerate overnight. The following day remove shanks from the braising liquid and set aside or refrigerate until ready to serve.
Strain the braising liquid, pressing to remove solids. Add the port to the braising liquid and reduce to 8 cups.
To serve, heat shanks with braising liquid, until hot. Place shank in middle of the bowl with roasted carrots and turnips around them. Spoon 1⁄2 cup braising liquid over each shank, and spoon sauce verde over roasted turnips and carrots.
Carrots and turnips:
Cut into 1” pieces.
Coat in olive oil, salt, and pepper.
Roast 400℉ until just starting to brown, ~ 20-30 minutes