Make the sauce: In a small bowl, whisk soy sauce, rice vinegar, honey, sesame oil, sriracha, broth, and cornstarch until smooth. Set aside.
Prep the veggies: Slice onions and cut vegetables into bite-size pieces.
Aim for similar sizes so they cook evenly.
Brown the chicken: Heat a large skillet or wok over medium-high. Add oil, then ground chicken. Break it up with a spatula and cook until no longer pink and lightly browned, 4–6 minutes.
Season with a pinch of salt and pepper.
Add aromatics: Stir in garlic and ginger. Cook 30–60 seconds until fragrant, stirring often so they don’t burn.
Cook the veggies: Add onion and mixed vegetables. Stir-fry 3–5 minutes until crisp-tender.
If using harder veggies like broccoli or carrots, cook them 1–2 minutes longer.
Sauce it up: Give the sauce a quick stir (cornstarch settles), then pour it into the pan. Toss everything to coat. Simmer 1–2 minutes until the sauce thickens and clings.
Taste and finish: Adjust with more soy for salt, vinegar for brightness, or sriracha for heat.
Garnish with green onions and sesame seeds.
Serve: Spoon over hot rice or toss with noodles. Eat right away for the best texture.