Prepare the Sauce: In a small bowl, whisk together rice wine vinegar, soy sauce, and coconut sugar (if using). Set aside.

Cook the Vegetables: Heat a large skillet or wok over medium-high heat. Add a splash of water or a small amount of oil to the pan, then add the garlic, ginger, and red onion. Cook for 1–2 minutes until fragrant.

Add the Broccoli and Mushrooms: Add the broccoli florets and sliced mushrooms to the skillet. Stir-fry for 3–4 minutes, adding vegetable broth or water as needed to prevent sticking.

Incorporate the Carrots and Cashews: Stir in the shredded carrots and cashews (or water chestnuts). Cook for an additional 2–3 minutes until the vegetables are tender-crisp.

Add the Sauce: Pour the prepared sauce over the stir-fry, tossing everything to coat evenly. Cook for another 1–2 minutes to heat through and allow the flavors to meld.

Finish and Serve: Sprinkle with sesame seeds and crushed red pepper (if using) before serving. Serve hot over steamed rice, quinoa, or noodles for a complete meal.