1. Place cauliflower in a dish, sprinkle with 2 Tbsp. water and microwave on high until tender, 3 to 4 minutes. In a small bowl, whisk together honey, hot sauce, broth, cornstarch, 2 Tbsp. soy sauce and 2 Tbsp. rice vinegar.
2. In a large skillet or wok, warm 2 Tbsp. oil over high heat. In a bowl, toss chicken with remaining 1 Tbsp. soy sauce and 1 Tbsp. rice vinegar. Stir-fry until chicken is no longer pink. Transfer to a clean bowl.
3. Add remaining 1 Tbsp. oil to skillet. Stir-fry garlic, ginger and white and pale green parts of scallions until fragrant, about 30 seconds. Return chicken to skillet with cauliflower and sauce. Cook, stirring, until sauce thickens, 2 to 3 minutes. Sprinkle dark green scallion bits on top. Serve on rice, if desired.