Heat vegetable oil in a large skillet or wok over medium-high heat.
Add minced garlic and sliced onion to the skillet. Stir-fry for 2-3 minutes until fragrant and onion starts to soften.
Add bell pepper, broccoli, carrots, mushrooms, snap peas, and cabbage to the skillet. Cook, stirring frequently, for 5-7 minutes until vegetables are tender yet crisp.
In a small bowl, mix together soy sauce, hoisin sauce, and sesame oil. Pour the sauce over the vegetables and toss to coat evenly. Season with salt and pepper to taste.
Serve the veggie stir-fry hot over cooked rice or noodles.
