Sieve the maida and add sugar and salt. Rub the butter into the flour using your fingertips until the mixture resembles bread crumbs.

Sprinkle chilled milk over the flour mixture and gently bring it together without kneading. Cover the dough with a plastic bag and refrigerate for 10–15 minutes.

Roll out the dough to about 1/8-inch thickness and cut into rounds. Press the rounds into pie tins, trim the excess dough, and prick the base all over with a fork.

Preheat the Oxy Fryer for 5 minutes. Arrange the pie shells in the fry basket and cook at 140°C for 15–20 minutes, until lightly golden. Remove and allow them to cool.

Heat oil in a pan and sauté the onions until light golden. Add the vegetables and capsicum, and sauté for 5–6 minutes. Add the seasonings and tomato puree, cook for another 2–3 minutes, then add salt and pepper. Allow the filling to cool.

Melt butter in a pan, add maida, and stir for 30 seconds until frothy. Reduce the heat and gradually add milk while stirring continuously. Cook until the sauce coats the back of a spoon, then add sugar, salt, and pepper. Remove from heat and mix some grated cheese into the filling.

Spread grated cheese over the base of each half-baked pie shell, followed by the vegetable filling and white sauce. Top with more grated cheese and garnish with olives and capsicum juliennes. Air fry again at 160°C for 8–10 minutes, until the cheese turns golden brown. Serve hot with tomato sauce.