Season the meat with salt and pepper, then coat it with flour.
Heat the oil in a pot, add the meat and brown it for a few minutes over medium heat, until it is evenly browned.
Add the onions and celery, cover and cook for 10 minutes to tenderize the vegetables.
Add the garlic and tomato paste, then continue cooking for 1 minute.
In the meantime, infuse the tea:
Put the tea in a large heat-resistant container, then pour the boiling water over it.
Let it steep for 4 minutes, then pour it into the pot, straining it.
Add the vinegar, orange zest, cinnamon, and ginger.
Reduce the heat, cover and cook for 2 hours, or until the meat is tender.
Add the sweet potatoes and honey, then season with salt and pepper to taste.
Continue cooking for another 30 minutes, or until the sweet potatoes are tender.
Sprinkle with coriander and serve.