Cut the cauliflower into medium to large size florets & wash them thoroughly. Allow them to dry completely before adding them to the batter. If there is any water remaining in the florets it will make the batter runny.
Mix all batter ingredients together. Add the water last, slowly to create a fairly thick batter. Add the dry cauliflower florets & mix well so that each floret gets well coated with the batter. Marinate for between 30 minutes to 4 hours.
When ready to make the dish, heat oil in a deep sided pan on medium-high heat. Once the oil is hot, lower the heat to medium and add the florets a few at a time deep frying until golden brown and crispy. Don’t fry them on high flame as the cauliflower needs to be cooked from inside too.
Remove on absorbent paper to drain any excess oil. Continue frying the remaining florets in similar manner. Keep these crunchy florets aside.
In a small container, mix the soy sauce, ketchup, sriracha sauce and white vinegar. Set aside.
Heat oil in a large frying pan or skillet. Add ginger, garlic paste and white part of the spring onions. Saute for two minutes then add the sauce. Mix well and saute for 1 min until the sauce thickens. Add 1/2 tsp sesame seeds (reserve 1/2 tsp sesame seeds for garnishing) along with the salt & pepper, to taste.
Just before serving, increase the heat to high and add the crunchy florets into the sauce. Stir fry for 2 mins so that the florets get well coated with the sauce. Garnish with the spring onion greens and remaining sesame seeds. Serve hot.