Prep your ingredients. Cut the broccoli into small, even florets.
Slice the onion thinly. Mince the garlic and grate the ginger. Having everything ready makes the stir-fry go smoothly.
Make the sauce. In a small bowl, whisk together soy sauce, rice vinegar, brown sugar or honey, and red pepper flakes if using.
In another cup, whisk the cornstarch into the chicken broth until smooth. Set both aside.
Blanch or steam the broccoli (optional but helpful). For crisp-tender results, steam or blanch the florets for 2 minutes until bright green, then drain well. This step prevents undercooked stems and overcooked tops.
Brown the turkey. Heat a large skillet or wok over medium-high.
Add 1 tablespoon oil, then the ground turkey. Season lightly with salt and pepper. Cook, breaking it into small crumbles, until no longer pink and lightly browned, 5–7 minutes.
Remove to a plate if the pan is crowded.
Sauté aromatics. In the same pan, add another drizzle of oil if needed. Add onion and cook 2–3 minutes until starting to soften. Stir in garlic and ginger and cook 30 seconds until fragrant.
Don’t let them burn.
Add broccoli and turkey back to the pan. Toss everything together. If you skipped pre-cooking the broccoli, add a splash of water and cover for 2–3 minutes to help it steam through.
Pour in the sauce. Stir the soy-vinegar mixture into the pan. Give the cornstarch slurry a quick stir and pour it in as well.
Cook, stirring, until the sauce thickens and coats the turkey and broccoli, about 1–2 minutes.
Finish and taste. Turn off the heat. Drizzle in sesame oil and taste. Adjust with a pinch of sugar for balance, more soy sauce for salt, or a splash of vinegar for brightness.
Garnish and serve. Top with sliced green onions and sesame seeds.
Serve over warm rice, quinoa, noodles, or cauliflower rice.