In a mixing bowl, whisk together plain Greek yogurt, mayonnaise, minced shallot, finely chopped parsley, cilantro, pressed garlic, extra virgin olive oil, red wine vinegar, and kosher salt until smooth and creamy. Set aside.

In a small bowl, combine garlic powder, kosher salt, and freshly cracked black pepper. Coat the chicken breast on all sides with the seasoning mix.

Heat avocado oil in a skillet over medium heat until shimmering. Add the seasoned chicken breast and cook for 4-5 minutes on each side until fully cooked. Remove from skillet and let rest for 5 minutes before shredding.

In the same skillet, sauté sliced jalapeños and red onion for 3-4 minutes. Remove from heat.

Return the shredded chicken to the skillet and combine with cooked jalapeños and red onions. Stir in chopped cilantro.

Warm tortillas in a dry skillet for 30 seconds on each side. Assemble by layering lettuce, chicken mixture, avocado, and feta on each tortilla. Drizzle with chimichurri sauce.