Fish and prawn gratins

Name: Fish and prawn gratins
Prep time: 12 min
Cook time: 28 min
Total time: 40 min
Cuisine: British
Ingredients: 340g bag baby spinach roughly chopped; 400g can chopped tomato with garlic and herbs; 225g sustainable white fish fillets, chopped into large chunks; small bunch basil shredded; 100g cooked and peeled prawn; 2 tbsp finely grated parmesan; 2 tbsp breadcrumb; 2 tbsp oats; 170g broccoli boiled or steamed, to serve