In a large pot melt the butter. Add garlic and onion, cook for 2 minutes until onion is almost translucent. Add capsicum and cook for 2 minutes.
1 tbsp butter, 1 chopped onion, 2 cloves garlic, 1 green capsicum
Add beef and cook, breaking it up as you go, until it changes from red to brown. Add remaining ingredients. Mix well, then turn heat down to medium low.
500 g beef, 1 tbsp mustard, 1.5 tbsp brown sugar, 1/2 cup ketchup, 2 tbsp Worcestershire sauce, 1 tbsp tomato paste, 400 g tomato paste, 1 beef cube, Black pepper as per taste
Cover and cook for 30 minutes, stirring once or twice to make sure it doesn't catch on the base. Remove lid and give it a good stir for a minute. Mixture should be thick, not runny and saucy.
Toast rolls. Pile on lots of filling, immediately top with cheese Top with lid and serve immediately!