Place a 1/2 cup of cake flour in a ziplock bag. Add the cauliflower and shake until well coated. Dump the coated cauliflower into a bowl and set aside.
Line a large baking sheet with paper towels for draining and set aside.
Fill a skillet with canola oil until there is 1 inch of oil. Heat on medium until the temperature reaches 360 degrees Fahrenheit. If you don’t have a deep-fry thermometer, dip the handle of a wooden spoon into the oil. If the oil starts bubbling, it’s hot enough. The bubbles will be extremely small and will seem to fizz up to the surface.
While the oil heats put the egg yolk in a medium-sized bowl along with the ice cold water and mix. Add the ice cubes.
Add the remaining 1 cup cake flour, and barely mix it. You want a loose lumpy batter with pockets of dry flour visible. It’s better to poke the mixture rather than stir or whisk it.
Add the sesame oil to the canola oil and allow the temperature to rise back to 360 degrees.
Dip the cauliflower into the batter and lay it in the hot oil.
While the cauliflower cooks, dip your fingers into the batter and sprinkle some directly onto each piece of cauliflower.
Cook for about 2 minutes, until the batter is golden brown. Use a slotted spoon to scoop up the fried loose bits of batter and place them on the paper towels along with the fried cauliflower. They make a great crunchy topping.
Remove and place the cauliflower on paper towels to drain. Sprinkle salt and pepper over the fried cauliflower bites and repeat until all the cauliflower is fried.
Place the cauliflower tempura in a large bowl and add the Honey Ginger Sriracha Sauce, mixing until the cauliflower is coated to your liking. Serve alone, with plain rice, or with No-Fry Pineapple Rice Salad.