Chop the spring onions - white and green parts separately.
Chop the garlic.
Grind 2 tablespoon white rice in a spice or coffee grinder to a powder.
Cooking
1. Prep the cauliflower
Add 1 cup water to the inner liner of the instant pot, arrange the cauliflower florets in a steamer basket, sprinkle ¼ teaspoon salt on the florets and place the basket in the pot. Set the cooker on pressure cooking mode (low) for 0 minutes. When the timer beeps, release the pressure (Quick Pressure Release).
If you don't have an instant pot, bring a pot of water to boil on the stovetop, add 1 tablespoon salt and put in the cauliflower florets. Switch off the heat after 2 minutes and let the cauliflower sit in the hot water for 2 minutes more. Drain the water and keep the cauliflower aside.
2. Make the batter
Sift the cornflour, all-purpose flour and rice flour in a bowl. Add water little by little and lightly whisk with a fork until you get a batter of coating consistency. Put the cooked cauliflower in this and mix well.
3. Fry the cauliflower florets in hot oil
Heat enough oil in a wok or frypan to deep-fry the cauliflower and heat it until it is smoking hot. Add the cauliflower florets, taking care not to over-crowd the wok. As soon as the florets start turning brown (30-40 seconds as the oil is very hot), take them out onto some kitchen paper.
4. Make the manchurian sauce
Heat 2 tablespoon oil in a frypan and add the spring onion whites, spring onion greens (half) and garlic. Saute for two minutes, then add all the sauces - soy sauce, hot sauce and ketchup. Add the brown sugar and black pepper powder as well. Add half a cup water and simmer for 5 minutes. To bring the sauce to a coating consistency, dissolve 1 teaspoon cornflour in 3 tablespoons water and add to the sauce. Stir until the sauce thickens.
5. Add the fried cauliflower to the manchurian sauce
Add the fried cauliflower to the manchurian sauce and turn off the heat. Toss until the cauliflower has absorbed most of the sauce. Finish with a garnish of the remaining spring onion greens.
Note: This is a dry cauliflower manchurian recipe and you can have it with a fork. However, if you want to make a meal out of it, cook some rice or spaghetti according to package instructions. Spoon the cauliflower manchurian over the rice or spaghetti and serve warm.
Notes
The cauliflower should not be over-cooked. It should still be firm and crunchy after you steam or blanch it.
Rice flour gives a crispy texture to anything it's added to, so don't skip it while making the batter.
Flash fry the cauliflower florets in very hot oil for a golden-brown, crisp exterior and remove quickly once done.
Don't cook the cauliflower in the sauce otherwise it will become too soft. When the sauce is ready, switch off the heat and toss the florets in the sauce until they have absorbed the liquid.
Serve the manchurian as soon as you can after making it. If you keep it for too long, the vegetables will lose their crispiness and become soggy.