Heat the oil, preferably in a cast-iron or non-stick skillet.
Add the onions, stir-fry for a minute, then add the remaining vegetables.
Sprinkle the garlic powder and adobo seasoning.
Stir-fry the veggies until the peppers get fairly tender but still have a strong bite. I like to let the veggies char a bit because it adds great flavor.
Season with pepper and check if more salt is needed.
Top with chopped coriander leaves and serve hot.
These would be great either as a side dish or served inside a wrap with felafel or baked tofu.