Make the green chutney using this recipe here and set it aside. It is also possible to use green chutney from the supermarket. Get your favourite brand from the Indian or Pakistani grocery store.
Add the diced onion, and cook for about 1 minute, and then add the diced capsicum. Cook for 2 – 3 minutes till soft and translucent. Season with salt. Remove the vegetables and set aside.
Pre-heat oven to 180°C / 360°F (160°C fan forced). It is also possible to make the sandwiches in the airfryer. In that case use the fan forced temperature settings.
Slice the Turkish bread (or whatever bread you are using) in half.
Place 1 – ½ tablespoon of green chutney on the bottom, and then top off with vegetables. Add the grilled paneer, and then top with shredded cheese.
Place the paneer tikka sandwiches on a baking tray and bake in the oven for about 8 - 10 minutes, till the bread is toasted and the cheese has melted. In the air fryer this will take about 5 - 8 minutes.