From a fantastic site I stumbled upon the other day. I'm posting the original recipe but I made it slightly differently-same amount of sauce, but only enough meat and sweet potato for the two of us as we love tons of sauce over our rice.
Preheat oven to 160°C Heat a large flameproof ovenproof pan over a high heat, spray with oil. Add beef in batches. Cook until browned. Remove and set aside.
Return pan to a medium-high heat. Spray with oil. Add onion. Cook, stirring occasionally, for 5 minutes. Add garlic, ginger and curry paste. Cook for 1 minute. Return beef to pan. Add tomatoes and water and fish sauce or soy sauce if using. Stir to combine and bring to the boil. Cover and place in oven for 1 hour.
Add sweet potato, stir, and return to oven for 30 minutes. Remove and stir through sugar. I garnished with a little chopped fresh coriander and basil but it wasn't in the recipe.