In a small bowl, whisk together the honey, water, soy sauce, vinegar, and cornstarch until smooth.
Pat the chicken dry with paper towels and cut into 1-inch pieces. Season with half of the kosher salt.
Heat 1 tablespoon oil in a large skillet over medium-high heat.
Add the chicken in a single layer and cook for 8–10 minutes, turning occasionally until browned. Transfer to a bowl.
Add the remaining tablespoon of oil to the skillet.
Add the zucchini and season with the remaining salt. Cook undisturbed for 1 minute, then stir and cook another minute.
Stir in the garlic and the white parts of the scallions. Cook for about 30 seconds until fragrant.
Return the chicken and any juices to the skillet.
Stir the sauce once more and pour it into the skillet.
Cook, stirring frequently, until the sauce thickens and the chicken is fully cooked, about 1–2 minutes.
Garnish with the sliced scallion greens and serve immediately.
This Honey Garlic Chicken and Zucchini Skillet is delicious served over steamed rice, noodles, or cauliflower rice.