Cut celery, carrot and onions into small pieces (or run them through food processor.)
Your meat should be cut into 3 cm strips, sprinkle the flour on top and mix all the meat with flour till they are all covered evenly with flour, remove excess flour.
Heat the pan in medium heat, add the olive oil, add in all the vegetable chunks, stir them till they are brown and soft for 2 minutes.
Add the meat and stir till they are brown in higher heat for 3 minutes.
Add the white wine and mix till wine is evaporated over high heat.
Add age stock and pinch of salt, cover the lid, let it simmer for 30 minutes in low heat.
Add the sweet potatoes, tomato paste, salt, black pepper and rosemary sprigs, make sure everything is covered with stock. Stir and cook for another 45 minutes.
Remove rosemary sprigs before serving, your dish is ready!