How to Make It
In a small bowl, whisk together 3 tablespoons of vegetable oil with the garlic, salt, chile powder, ground cumin, paprika, sugar and fresh lime juice. Set aside.
Heat a large skillet over medium-high heat. Add one tablespoon of vegetable oil and then stir in the onions. Cook for 3 to 5 minutes or until the onions are soft and slightly caramelized. Stir in the balsamic vinegar and cook for another minute. Remove the onions from the pan and set aside.
In the same pan, add the remaining tablespoon of oil and then stir in the chicken. Cook for 2 minutes or until the chicken is lightly browned. Stir in the bell pepper and cook with the chicken for 3 to 5 minutes or until the vegetables are tender.
Stir in the spice mixture and cook for another 2 minutes or until everything is well combined and heated through. Season with salt and pepper to taste. Serve with tortillas and optional toppings.