Peel and chop the onion. Peel and grate or crush the garlic. Roughly chop the tomatoes. Grate the carrot and courgette, keeping them separate.
Warm a frying pan over a medium heat. Add 1 tbsp oil. Fry and stir the onion and carrots for 4 mins till softened. Add the garlic and cook for 1 min.
Tip the lamb mince into the pan and break up with a wooden spoon. Fry for 3-4 mins till browned, stirring often. Add the chopped tomatoes. Crumble in the stock cube. Pour in 200ml boiling water. Cover and simmer over a low heat for 20 mins.
Finely shred the mint leaves and set aside for later.
When the lamb has cooked for 10 mins, tip the penne into a pan. Pour over enough boiling water to cover. Add a pinch of salt. Cook for 8-9 mins till the pasta is al dente (soft but with a slight bite). Drain then put back into the pan. Add ½ tbsp oil. Put the lid back on to keep warm.
Sprinkle 1 tsp of the oregano into the lamb. Warm for 1-2 mins. Taste and season. Add in the grated courgette and stir through.
Tip the cooked pasta into the lamb ragu. Fold together. Serve in warm bowls with the shredded mint scattered on top.
Adding herbs such the oregano and mint right at the end of cooking ensures that no flavour is lost or destroyed during cooking. The mint stays green and flavourful whilst the oregano still packs a punch.