For the cauliflower:
1 small head cauliflower cut into bite-size florets
2 tablespoons cornstarch
1/2 teaspoon baking powder
½ teaspoon salt
Pinch of white pepper
1 egg or 2 egg whites
3 tablespoons soy sauce
1 tablespoon rice vinegar
1/4 cup water
1/2 cup all-purpose flour or rice flour
2 teaspoons toasted sesame seeds
2 to 3 cups peanut or canola oil, for frying
For the sauce:
2 teaspoons sesame oil
6 scallions, white part finely sliced, green part chopped into 1-inch pieces
3 cloves garlic, minced
1 tablespoon minced ginger
1 tablespoon whole hot chili red chili pepper, minced
1/2 cup vegetable broth
1/4 cup soy sauce
3 tablespoons rice vinegar
2 tablespoons mirin
3 tablespoons sugar
1 tablespoon cornstarch
Sesame seeds, for garnish (optional)
1. 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 needed).
2. Heat the oil in a medium cast iron skillet 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 fully in the batter, then place in the oil. Pan-fry the cauliflower until it’s golden on all sides, 4 to 5 minutes. Drain on absorbent paper towels.
4. In a medium pot, heat the sesame oil over medium heat. Add the finely-chopped white scallions, garlic, ginger and chiles, and cook until fragrant, 1 to 2 minutes.
5. Add the broth, soy sauce, rice vinegar and mirin, and bring to a simmer over medium heat. Simmer for 5 minutes.
6. In a small bowl, whisk the sugar and cornstarch to combine. Pour about ¼ cup of the hot sauce over the 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 and has good flavor, 7 to 9 minutes more.
8. Add the cauliflower to the pot and toss to coat until the cauliflower is rewarmed, 4 to 5 minutes. Serve immediately, garnished with sesame seeds and with a side of steamed rice.