Preheat the oven to 200°C/ fan 180°C/ gas 6. Fill a large saucepan with cold water and add the potatoes. Bring to the boil, then turn down the heat and simmer for 10 minutes.
Meanwhile, heat the olive oil in a frying pan and sauté the onion, until soft. Add the carrots to the onion with the beef mince and fry, stirring for a few minutes. Add the soup and simmer for 10 minutes.
Drain the cooked potato. Spoon half the mince mixture into a large ovenproof dish. Lay half the courgettes over the mince with half the cooked potato. Spoon over the remaining mince, and layer with the remaining courgette and potato. Sprinkle with the dried mixed herbs and bake for 40 minutes, until golden.
Cook's tip: try swapping beef mince for vegetarian mince.