Preheat the oven to 200°C (180°C fan, gas mark 6). Line a baking tray with baking parchment.
In a small bowl, mix 120ml tomato purée with 60ml water. Stir in 1 tsp garam masala, ½ tsp ground cumin, ¼ tsp turmeric powder, ½ tsp freshly grated ginger, 1 minced garlic clove, ¼ tsp salt and a pinch of black pepper until smooth.
Cut the paneer into 1cm cubes.
Thinly slice half a small red onion and half a small green pepper.
Arrange the naans on the prepared tray. Spread half the spiced tomato sauce evenly over each, leaving a small border.
Scatter the paneer cubes, sliced onion and pepper over the naans.
Sprinkle 120g grated mozzarella evenly over each naan.
Bake for 10–12 minutes, or until the cheese is melted and bubbling and the naans are golden-brown and crisp around the edges.
Remove from the oven and leave to cool for 1–2 minutes. Sprinkle the chopped coriander over the naans, then slice and serve.
Store any leftovers in an airtight container in the fridge for up to 3 days. Reheat in the oven until piping hot before serving.