Prep the chicken: Pat the chicken dry. Toss with salt, pepper, garlic powder, and smoked paprika.
This helps build flavor and browns better.
Sear for color: Heat oil in a large skillet over medium-high. Add chicken in a single layer and cook 3–4 minutes per side until browned and almost cooked through. Work in batches if needed.
Transfer to a plate.
Build the sauce base: Lower heat to medium. Add butter to the skillet. Stir in minced garlic and cook 30–45 seconds until fragrant, not browned.
Deglaze: Pour in tamari, honey, sweetener, vinegar, and chicken broth.
Scrape up browned bits from the pan for extra flavor.
Simmer and thicken: Bring to a gentle simmer. Whisk in a tiny pinch of xanthan gum (start with 1/4 teaspoon), sprinkle it evenly to avoid clumps. Stir and let the sauce thicken for 1–2 minutes.
Add more in small pinches until it lightly coats a spoon. If using arrowroot, mix with water first, then stir into the simmering sauce and cook 1 minute.
Finish the chicken: Return the chicken and any juices to the skillet. Add red pepper flakes if using.
Simmer 2–3 minutes until the chicken is cooked through and the sauce is glossy.
Season and enrich: Stir in toasted sesame oil. Taste and adjust salt, sweetener, or vinegar. The sauce should be sweet-salty with a gentle tang.
Serve: Garnish with sesame seeds and green onions.
Serve hot over cauliflower rice or with steamed broccoli.