Step 1: Take cornstarch in a bowl and mix little chicken stock. Keep this aside. Heat oil in a non stick wok or a deep pan. Put garlic and saute it till golden brown colour.
Step 2: Now add the diced and separated onion and capsicum. Saute for sometime.
Step 3: Add the chicken pieces and salt. After sometime, add tomato ketchup, red chilli paste and little chicken stock. Let it cook for sometime. If you feel the dish is dry, add more chicken stock to it. Cook till the chicken is cooked throughly. All these should be done on high heat and hence the cooking is done fast.
Step 4: Now add the cornstarch. Mix well. When the gravy thickens, add the chopped spring onion. Serve it hot.