Heat sesame oil in a large skillet over medium heat.
Add minced garlic and sliced onion, stirring until fragrant.
Toss in the shredded cabbage and mix well.
Add the sliced bell peppers and julienned carrots.
Stir-fry the vegetables for about 5-7 minutes until tender-crisp.
Pour soy sauce over the mixture and stir to combine.
Season with salt and pepper to taste.
Cook for an additional 2-3 minutes, allowing flavors to meld.
Remove from heat and garnish with green onions if desired.
Serve hot and enjoy your vibrant dish!