Cut beef into 1 inch thick cubes. Season with onion powder, garlic powder, paprika, salt and seasoning cube.
Peel and cut potatoes into bite size chunks.
Heat the oil in a large non-stick frying pan or wok until really hot. Fry the beef and sprigs of thyme for 1 minute on each side.Add potatoes and beef stock .Cook on high heat for 15minutes.
While potatoes and beef are cooking, slice your bell peppers .Add oil to a skillet, stir fry garlic,onions, tomatoes and bell peppers.
Add the vegetables to the potatoes and beef. Toss gently for a few minutes. Serve immediately.