Add chopped onion, carrot, celery and sweet potato to the slow cooker
In a large plastic bag combine flour, stock powder, gravy powder and pepper
Add meat to this bag and toss meat in this combined flour mix to coat
Lay this floured Osso Bucco over the vegetables already in the slow cooker
Combine passata, red wine, & garlic and pour over
Scatter with fresh parsley, bay leaves and fresh rosemary
Cook on high for 2.5hrs then low for 4.5hrs
I gently turned the meat over at around half way through cooking time
Alternatively, this could also cook for 9hrs on low
After cooking time is over, remove and discard the bay leaves and rosemary sprigs. Scoop any fat that has pooled on top of dish and discard.
Gently remove meat and veg to a covered plate to keep warm while you transfer the cooking liquids to a saucepan. Add a cornflour slurry to thicken over high heat in approx 5mins while stirring continuously as it thickens
Spoon vegetables into serving bowl, place Osso Bucco on top of veg, then pour over sauce.
Garnish with a little extra fresh parsley to serve