Heat your oven to 350F/180C and turn your stove top burner to medium-high.
Place a large dutch oven (I use this, it has a 7-qt capacity, by All Clad) on stove top and warm the corn oil. Season your lamb shanks with salt and place in a single layer (do not overlap shanks; you may have to do this in batches) in the dutch oven.
Once the shanks have caramelised nicely on both sides, (about 5-7 minutes), remove and set aside. You'll notice that a lot of fat would have rendered. Drain all the fat from the dutch oven.
Place lamb shanks back into dutch oven and add wine, chicken stock, cinnamon stick, half of the saffron powder, the juice of 2 oranges and lime.
Cover with lid and place in the oven.
Oven times vary, so you will have to keep an eye on the shanks. In my kitchen, it takes 2.5 hours for the lamb shanks to be falling-off-the-bone-tender.
Braise in the oven for 2 hours uncovered. At the 1.5 hour mark, check for tenderness gently with a fork. This will be a good indication of how much more time is required for doneness. Turn the shanks over once, very gently. If you feel too much liquid has evaporated, add some boiling water.
After the 2 hour mark, braise for 30 minutes without the lid. By this time the meat should be almost falling off the bone. There should still be some shallow liquid in the dutch oven.
Remove from the oven and allow to rest for 20 minutes.