On medium- high heat, add oil in a pan and add the chopped onions and saute until translucent.
Add the ginger-garlic paste and saute for 1 minute.
Add the shredded chicken and saute for 1 minute.
Then add the following spices - black pepper powder, crushed red chili flakes, oregano, cumin powder, chicken powder and siracha. Saute for 1 minute more.
Now add the all purpose flour, saute for 1 minute and add the milk stirring continuously. The mixture will start to thicken.
Taste for salt and adjust and remove from the heat when the mixture is .relatively dry.
Allow the mixture to cool completely.