Mediterranean Tilapia Casserole

Ingredients

• 1 small onion
• 90 ml (6 tbsp) olive oil
• 250 ml (1 cup) Arborio rice, not rinsed
• 1 L (4 cups) fish stock
• 2 zucchini, sliced thinly
• 1 clove garlic, chopped
• Salt and freshly ground pepper, to taste
• 450 g (1 lb) Italian plum tomatoes, sliced thinly
• 4 fillets, 115 g (4 oz each) tilapia
• 50 ml (1/4 cup) fresh basil, shredded