There is so much variety when it comes to pasta these days. You could serve this with quinoa spaghetti, buckwheat pasta or mung bean noodles, for instance. It would also work well with spiralised raw courgettes or celeriac. The grated carrots add sweetness to the meatballs, sneaking in some extra veg while helping the meat to go a bit further. The meatballs freeze well, so why not make a double batch and freeze half raw? As both the meatballs and sauce use onions and garlic, you effectively save a step by frying it all up to begin with.