Spray frying pan with Canola Oil, cook sausages, onions and garlic together until cooked, remove from pan, slice sausages evenly.
In the frying pan melt 4 tablespoons margarine on low heat, slowly add flour, stirring constantly to combine without lumping. Add enough water stirring briskly to make a sauce, removing any lumps (up to 2 cups of water).
Add curry Powder, salt and pepper and continue to stir until all until combined.
Transfer sauce into slow cooker and put sausages, onion and garlic into the sauce. Add all veges. Mix till combined.
Cook on high for 2 hours and then low for 4 hours.
Serve on a bed of boiled/steamed rice