Season the short ribs all over with salt and pepper then dust with flour. Heat a 7-quart Dutch oven over medium-high heat, add the olive oil and heat through. Working in batches, sear the ribs on all sides, about 5 minutes total. Remove to a plate and repeat with the remaining ribs.
Heat oven to 325ºF (170ºC).
Return the pot to medium heat and add the onion and celery and sauté until tender, about 6 minutes. Stir in the tomato paste followed by the coriander and cumin.
Add the short ribs back to the pot along with the carrots, chilies, lime, orange zest and oregano. Pour the orange juice and stock into the pot and bring to a boil then cover and move the pot to the oven.
Cook, turning the ribs occasionally, until the meat is fork tender, about 3 to 3½ hours.
Transfer the short ribs and carrots to a large baking dish and cover with foil to keep warm. Strain the cooking liquid through a fine-mesh strainer into a medium bowl then return the liquid to the pot.
Bring to a boil over medium heat, then reduce the heat to medium-low and simmer until thickened and reduced by half, about 20 minutes. Season with salt and pepper. Add the ribs and carrots and turn to coat.