In a large pot, heat the oil and add the onions. Fry the onions on a medium high heat until caramelized and golden brown. The onions should be a deep, dark brown but not burnt. Take out the caramelized onions and place on kitchen paper to drain excess oil and let cool for a few minutes.
Add the caramelized onions and yogurt to a blender or a food processor and blend until smooth. You may need to add 1-2 tablespoons water to get a smoother paste. Set aside.
In the same pot, add the chicken and ginger garlic paste and cook on high heat until the chicken changes color and is no longer pink.
Add the Shaan Korma Masala and salt and cook for 5-7 minutes until the oil separates and you can no longer smell the rawness of the spices.
Add the yogurt-caramelized onions paste and water. Cook until it comes to a boil. Reduce the heat to medium-low, cover and let simmer for 15 minutes until you can see the oil separating from the curry.
Take off lid and bring to another boil by increasing the heat then and turn off the stove.
Garnish with chopped coriander. Serve with naan and white rice.