Prawn and Spinach Biryani

Ingredients

• 400 g can chopped tomatoes
• 2 tablespoons vegetable oil
• 1 large onion, halved and thinly sliced
• 1 red chilli, deseeded and thinly sliced
• 15 g fresh ginger, peeled and finely chopped
• 1 tablespoon ground cumin
• 1 tablespoon ground coriander
• 1 teaspoon ground turmeric
• 1/2 teaspoon ground nutmeg
• 1 cup (200 g) basmati rice, rinsed
• pinch of sugar
• 300 g baby spinach leaves, roughly torn
• 250 g peeled raw prawns, thawed if frozen