Gnocchi, Vegetable and Mozarella Bake

Ashamed to say that this served just 2 very hungry people... would easily stretch to 3 or 4 with a salad and a piece of bread on the side!

1 pack gnocchi
1 courgette
1 stick of celery
1 small white onion
1 tin chopped tomatoes
2 cloves garlic
1 tbsp tomato purée
2 sun dried tomatoes (optional, but we usually have a jar of them in oil lurking in the fridge)
1 tsp mixed herbs
1 ball mozzarella
Pinch salt and ground black pepper
Small handful of breadcrumbs

1. Chop the onion, courgette (chunky pieces) and celery and crush the garlic cloves. 
2. Soften over a low heat in an oven proof dish with a dash of oil for 5-10 minutes, stirring occasionally
3. Add the herbs, salt and pepper and stir through, then add the tin of tomatoes and the tomato purée. Add a small amount of water and stir through to combine
4. Leave with the lid on to simmer on a low heat until the courgette is softening, around 10 minutes
5. Meanwhile boil the gnocchi in salted water for 3-4 minutes until they rise to the surface, then drain
6. Stir the gnocchi into the tomato sauce to coat thoroughly then even out around the dish and turn off the heat
7. Lay thin slices of the mozzarella on top of the mixture, then sprinkle breadcrumbs over
8. Grill or bake at a high heat for 10 minutes or so, until the mozzarella has melted and the breadcrumbs begin to toast and crisp up