Cut the Cauliflower in florets keep aside.in kadai  add water and salt boil it, when it start boiling add Cauliflower florets in it and boil for 10 min on high flame. After that strain the water then keep aside. 

 In bowl add plain flour, cornflour and salt mix it. Add little by little water make no lumps remain batter . Add  boiled Cauliflower florets on it mix well, when you adding Cauliflower in  this batter, batter become thin, so add cornflour on it for nice thick coating to florets.

Heat the oil in pan, fry Cauliflower  florets  on it. Take out fried florets in tray. Wait.. frying step is not complete. Heat the oil on high flame , add fried florets on it. Fry once again in oil, till crispy and golden brown in  colour, on high flame.

Take out  florets and keep aside.  In big kadai  add 2 tbsp of oil. Add chopped garlic and chopped onion on it mix well on high flame.  Add red chilli sauce and soy sauce mix well. Add tomato ketchup, salt and spring onion  mix well. 
Add 1 cup of water when it start boiling  add cornflour celery  mix well  till Manchurian sauce  become thick. Add fried  Cauliflower florets on it mix well. 

Garnish with spring onion green,  Serve hot.