Wash and slice the zucchini and yellow squash into thin rounds. Slice the bell pepper and onion.

Heat olive oil in a skillet over medium heat. Add the minced garlic and sauté for 1 minute.

Add the sliced onion and bell pepper to the skillet and cook for 3-4 minutes until softened.

Add the zucchini and yellow squash, salt, black pepper, and oregano. Stir-fry for another 5-6 minutes until the vegetables are tender but still crisp.

Remove from heat and serve immediately.