1. Prepare the Cauliflower: In a medium bowl, whisk the flour, cornstarch, baking powder and salt to combine. In a liquid measuring cup, whisk the eggs, soy sauce and vinegar to combine. Slowly pour the egg mixture into the flour, whisking constantly. You should end up with a thick but still dip-able batter (thin with a little water if it’s too thick).

2. Heat the oil in a medium cast iron skillet over medium-high heat until very hot (you can test it by dropping a small amount of batter into the oil—it should immediately sizzle and float).

3. Dip each piece of cauliflower in the batter to fully coat, then carefully place in the oil. Pan-fry the cauliflower until golden on all sides, about 5 minutes. Transfer to a plate lined with paper towels to drain the excess oil.

4. Make the Sauce: Meanwhile, in a medium saucepan, heat the sesame oil over medium heat. Add the finely-chopped scallion whites, garlic, ginger and chiles (if using), and cook until fragrant, about 2 minutes.

5. Add the broth, soy sauce, rice vinegar and mirin, and bring to a simmer over medium heat. Simmer for about 5 minutes.

6. In a small bowl, whisk the sugar and cornstarch to combine. Pour about ¼ cup of the hot sauce over the cornstarch mixture, whisking constantly until the mixture is smooth and lump free. Return the mixture to the pot and bring to a simmer. Stir in the large pieces of green scallion.

7. Cook, stirring occasionally, until the mixture thickens, 7 to 9 minutes more.

8. Add the cauliflower to the pot and toss to coat until the cauliflower is rewarmed, about 5 minutes. Serve immediately, garnished with sesame seeds and served with a side of steamed rice.