Wash and chop the bell peppers, zucchini, cherry tomatoes, and red onion into bite-sized pieces. Mince the garlic and basil leaves.

Add olive oil to a wok or large skillet and heat over medium-high heat until shimmering.

Add minced garlic and sliced red onion to the hot oil. Sauté for 2-3 minutes until fragrant and slightly softened.

Add bell peppers and zucchini. Stir-fry for 7-8 minutes until vegetables are tender but still crisp.

Stir in cherry tomatoes, basil, salt, and pepper. Cook for an additional 2 minutes to soften tomatoes.

Drizzle balsamic glaze over the stir-fry, toss gently to combine, and remove from heat.