Restaurant Style Chicken Shashlik with Gravy Recipe/food

Go impress everyone with your restaurant-quality cooking skills. This restaurant-style chicken shashlik recipe is a quick and simple foolproof recipe perfected just for you
Ingredients:
-Boneless chicken cubes ½ kg (1 inch size)
-Soy sauce 1 tbs
-Sirka (Vinegar) ½ tbs
-Lal mirch (Red chilli) crushed 1 tsp
-Kali mirch powder (Black pepper powder) ½ tsp
-Namak (Salt) ½ tsp or to taste
-Chicken powder 1 tsp
-Lehsan paste (Garlic paste) 2 tsp
-Cooking oil 2 tbs
-Shimla mirch (Capsicum) cubes 1 Cup
-Pyaz (Onion) cubes 1 Cup
-Tamatar (Tomatoes) deseeded & cubes 1 Cup
-Cooking oil 2 tbs
-Lehsan (Garlic) chopped 2 tsp
-Adrak (Ginger) chopped 1 tsp
-Tomato ketchup 1 Cup
-Chilli sauce 3 tbs
-Soy sauce 3 tbs
-Sirka (Vinegar) 1 tbs
-Lal mirch powder (Red chilli powder) 1 tsp or to taste
-Kali mirch powder (Black pepper powder) 1 tsp
-Namak (Salt) ½ tsp or to taste
-Safed mirch powder (White pepper powder) ½ tsp
-Sugar 1 tsp
-Water 1 Cup or as required
-Chicken stock cube 1
-Cornflour 1-2 tsp
-Water 3-4 tbs
-Hara pyaz (Green onion) leaves chopped

Directions:
-In a bowl, add chicken, soy sauce, vinegar, red chilli crushed, black pepper powder, salt, chicken powder, and garlic paste & mix well, cover & marinate for 25-30 minutes.
-In a frying pan, add cooking oil, and marinated chicken, mix well & cook on medium flame for 6-8 minutes then cook on high flame until it dries up.
-Add capsicum,onion, tomatoes,mix well & sauté for a minute & set aside.
-In a wok,add cooking oil,garlic,ginger & mix well.
-Add tomato ketchup & mix well.
-Add chilli sauce,soy sauce,vinegar,red chilli powder,black pepper powder,salt,white pepper powder, sugar,mix well & cook for 1-2 minutes.
-Add water,chicken stock cube,mix well & bring it to boil.
-In cornflour, add water & whisk well.
-Now add dissolved cornflour,mix well & cook until it thickens.
-Add cooked chicken with vegetables & mix gently.
-Garnish with green onion leaves & serve!