Whisk the broth, soy sauce, vinegar, maple syrup, cornstarch and sesame oil in a small bowl. Set it next to the stove.
Heat a wok or large skillet over high heat until very hot. Add the neutral oil and swirl to coat.
Add the carrots and broccoli and stir-fry for 2–3 minutes. If the pan looks dry, add a tablespoon of water to create a little steam.
Add the pepper, snap peas and cabbage and stir-fry for 2 minutes more, until the vegetables are bright and crisp-tender.
Push the vegetables to the sides, add the ginger and garlic to the center and stir for 30 seconds until fragrant.
Stir the sauce again (the cornstarch settles), pour it in and toss for about 1 minute, until glossy and thickened.
Serve immediately over rice or noodles, scattered with sesame seeds and green onions.