Step 1

Preheat the oven to 450 degrees F (230 degrees C).

Step 2

Liberally grease 2 parchment-lined baking sheets with olive oil.

Step 3

In a medium-large mixing bowl, combine the flour, cornstarch, baking powder, garlic, ginger, and salt. Make a well in the middle and stir in the sparkling water, whisking with a fork to form a smooth batter.

Step 4

Add the cauliflower florets and gently toss to coat them evenly in the batter.

Step 5

Place the florets onto the baking sheets, allowing a space between each piece to help them crisp up in the oven (if they are too close, they will steam each other). Bake, turning once, until crispy and golden brown, about 10 minutes.

Step 6

Meanwhile, make the sauce: Place the brown sugar, ketchup, tamari, vinegar, sesame oil, sriracha and garlic in a small saucepan. Using a wooden spoon, mix well and bring to a gentle, bubbling simmer. Cook, stirring often, until it reduces into a glossy consistency that coats the back of the wooden spoon, about 10 minutes.

Step 7

Remove the cauliflower from the oven and tip into a bowl. Drizzle over the sweet and sour sauce, add most of the cilantro and scallions, leaving some behind for garnish, and gently toss to coat each floret.

Step 8

Transfer to a serving plate and sprinkle over the remaining cilantro and scallions before serving. Enjoy.