Heat oil in large pot over high heat. Add garlic and onion, cook 1 min. Then add capsicum and cook until onion is translucent.
Add beef and cook, breaking it up as you go.
Once the beef turns from red to brown, add remaining ingredients except cheese. Stir, bring to simmer, then turn the heat down to medium. Cover and cook for 12 min or until the macaroni is al dente, meaning just cooked, still a bit on the firm side. Will be watery, liquid is absorbed in next step.
Turn the stove OFF but leave the pot on the stove. Stir through half the cheese – it should be a bit saucy. Top with remaining cheese, put the lid back on and leave until the cheese melts - about 2 min.
Sprinkle with coriander, if desired, and serve immediately.
