Heat oil in a pan or kadai, add ginger, garlic, celery and saute on high for a few seconds till fragrant. Add salt, sugar, pepper, ketchup, vinegar, sriracha, soy sauce, stir and cook on medium for a few seconds till it sizzles. Add stir well, bring to a boil and simmer for 4-5 minutes. Mix cornflour slurry and add to the pot while stirring continuously, once it starts boiling, reduce the heat and simmer for 2-3 minutes till the sauce thickens and turns glossy.