Preheat the oven to 180°C, fan 160°C, gas 4. Put the naan breads on a baking sheet.
Spread 1 teaspoon of passata over each of the mini naan breads. Top with the sliced pepper and tomatoes, then add the torn mozzarella. Sprinkle over the dried oregano.
Bake in the preheated oven for 15 minutes, until the edges of the naan breads are golden and the mozzarella has melted.