Preheat oven to 200°C. Line a baking tray with baking paper.
Heat oil in a large frying pan over medium-high heat. Add onion, garlic and capsicum and cook, stirring, for 7 minutes or until softened. Add salami and tomato and stir for 3 minutes or until warmed through and tomato starts to soften. Remove pan from heat.
Warm pita pockets as per packet instructions. Cut in half. Using the back of a spoon, spread insides of pita halves with passata. Sprinkle half the cheese among pockets. Divide salami mixture among pockets and finish with remaining cheese.
Carefully place pita pockets on tray and bake for 18-20 minutes or until golden and crisp.