In a large skillet, heat the olive oil over medium heat. Add the finely chopped onion and sauté for 3-4 minutes until translucent.
Add the ground turkey or chicken to the skillet, seasoning with garlic powder, cumin, salt, and pepper. Cook for 7-10 minutes, stirring occasionally, until fully cooked through and golden brown.
While the meat is cooking, heat the corn tortillas in another skillet on low for about 1 minute on each side until warm and pliable.
In a mixing bowl, combine diced tomatoes, shredded lettuce, and sliced avocado. Drizzle with olive oil and toss gently.
Once the meat is ready, remove from heat and let it rest for 5 minutes.
Assemble the taco plate by placing the warm tortillas on serving plates. Add a generous scoop of the turkey or chicken mixture, top with the fresh salad, and finish with your choice of cilantro and lime wedges. Enjoy your homemade taco truck experience!