In a medium bowl, whisk together Greek yogurt, mayonnaise, minced shallot, chopped parsley, chopped cilantro, olive oil, red wine vinegar, minced garlic, and salt to taste. Blend until smooth and creamy.

Take chicken breast and season with garlic powder, salt, and pepper. Allow to rest for about 10 minutes.

Heat oil in a skillet over medium heat. Add seasoned chicken and cook for 4-5 minutes on each side until golden brown and internal temperature reaches 165°F. Transfer to a plate and let rest.

In the same skillet, add chopped jalapeños and red onions. Cook for 3-4 minutes, stirring frequently and deglazing the pan with water.

Return shredded chicken to the skillet with the vegetables. Stir in chopped cilantro and heat through for an additional 2-3 minutes.

Warm tortillas in a skillet or microwave. Layer with romaine lettuce, slices of avocado, chicken mixture, feta cheese, and drizzle with chimichurri sauce.