Bring the ½ cup vinegar to a boil and then reduce the heat to a simmer for 10 to 15 minutes. Watch it carefully and stir often to make sure it doesn’t burn. It should be thick and have a sticky consistency.

Heat the 1 tablespoon vegetable oil in a medium skillet on medium-high heat. Add the onion and bell pepper and cook for 5 minutes. Add the zucchini and squash and cook for 5 minutes. Add the 2 teaspoon chili powder, 2 teaspoon cumin, 1 teaspoon coriander, 1 teaspoon smoked paprika, ¼ teaspoon cayenne pepper (if you like hot food, if not add less or leave it out), and salt and pepper to taste and cook for 5 to 7 minutes, or until the vegetables are just fork tender.

Heat the tortillas and fill with the vegetable mixture. Drizzle the glaze over the taco.