Add the onions, garlic, celery, carrot and courgette and cook for five minutes, stirring occasionally, until the vegetables begin to soften.
Add the steak mince and fry, stirring frequently, until the mince is browned all over. Season well to taste.
Add the tomato puree, tinned tomatoes, Worcestershire sauce and beef stock. Reduce the heat and leave to simmer with the lid off, for approximately 15 minutes, or until the sauce is thick and reduced. Stir in the herbs.
Spiralize your courgettes. You can serve them raw or place them into a colander and pour over a kettle of boiling water. This will take away the 'raw' taste without compromising their structure.
Divide the courgette between four plates, top with a spoonful of bolognese and sprinkle with cheese, if desired. Serve immediately.