Prepare Chicken Filling: Heat cooking oil in a frying pan. Add sliced onion and fry until light golden. Add boneless chicken cubes and ginger garlic paste; mix well until chicken changes color.
Cook Chicken with Spices: Add paprika powder, turmeric powder, dried oregano, Himalayan pink salt, and soy sauce. Mix well and cook on medium flame for 4-5 minutes, then on high flame until the mixture dries up.
Add Cheese and Sauces: Remove from heat, add cheddar cheese and mix until melted. Let the filling cool, then add mayonnaise, chilli garlic sauce, and sriracha sauce. Mix well and set aside.
Prepare Pita Dough: In a bowl, combine warm water, caster sugar, and instant yeast. Mix well and let proof for 5 minutes until frothy.
Make Dough: Add warm milk, cooking oil, sifted all-purpose flour, and Himalayan pink salt to the yeast mixture. Mix and knead until a dough forms. Add cooking oil and knead for 1-2 minutes more.
Proof Dough: Grease the dough with cooking oil, cover with cling film, and let it proof in a warm place for 45 minutes to 1 hour or until doubled in size.
Shape and Fill Dough: Knead the dough until smooth. Take 80g portions, sprinkle dry flour, and roll out to 6 inches diameter. Place on a baking tray lined with a silicone baking sheet. Mark the dough in half with a dough cutter.
Assemble Bread Pockets: Apply soft butter on half of the rolled dough and fold the other half over it. Brush with milk, add sliced onion, mozzarella cheese, and sprinkle crushed red chilli flakes.
Bake: Bake in a preheated oven at 180°C (356°F) on the lower grill for 12-14 minutes.
Rest and Serve: Remove from oven and cover with kitchen cloth for 15 minutes. Add a lettuce leaf on each pita bread, spoon prepared chicken filling inside, and serve.