Preheat the oven to 200°C/gas mark 6. Heat 1 tbsp of the oil in a large frying pan and add the onion. Cook for 2-3 minutes before adding the carrot and mushrooms. Continue cooking for another 4-5 minutes until the carrots are just tender. Set aside to cool.
Pulse the chickpeas in a food processor, then add the cooked onion, carrot and mushrooms. Blitz and add the coriander, cumin and egg until it comes together. Roll the mixture into 20 balls using your hands and chill in the fridge for up to an hour.
Transfer to a baking tray lined with baking paper and cook in the oven for 40 minutes. Meanwhile, add the chopped tomatoes to the pan and season, then simmer for 7-8 minutes until the sauce has reduced and thickened slightly.
Meanwhile, put the courgettes through a spiraliser, then add to another pan with the remaining oil and cook for 2 minutes while stirring continuously.
Divide the spaghetti between four bowls and top with the meatballs, tomato sauce and cheese.