Preheat your oven to 330°F. In a large Dutch oven, heat the cooking oil over medium-high heat. Season the shanks with salt and pepper. Add the venison once the pan is hot and the oil is just starting to smoke. Cook on all sides until the meat is nice and golden brown. Work in batches if needed. Once browned, place in a braising pan.
Lower the heat to medium-low and add the onions, bell peppers, and garlic. Season with salt and pepper. Cook for about 8 minutes, stirring often, until the onions are translucent. Transfer to the braising pan.
Add the cumin seeds, oregano, cinnamon stick, bay leaf, chile powder, chipotles in adobo, and tomatoes to the braising pan.
Pour the stock and wine over the shanks. The shanks need to be about 3/4 of the way covered with cooking liquid. If you do not have enough, add a bit more stock.
Cover with aluminum foil, and cook in the oven between 4 to 5 hours, or until fork tender.
Let the braising liquid cool slightly and season to taste with salt and pepper.