Heat a skillet over medium heat, adding avocado oil. Once shimmering, toss in minced garlic and fresh spinach. Sauté for 3-4 minutes until spinach wilts and garlic becomes fragrant. Remove from heat and allow to cool.

In a large mixing bowl, add ground turkey, garlic powder, dried oregano, dried basil, kosher salt, and ground black pepper. Stir in the cooled spinach mixture, folding together until well combined.

Crack the large egg into the turkey mixture and mix gently to bind the ingredients. Fold in chopped sun-dried tomatoes and crumbled feta cheese, ensuring even distribution.

Form the mixture into four large patties, compacting them well. Place on a plate lined with parchment paper and refrigerate for 30 minutes.

Preheat a skillet or grill over medium-high heat with avocado oil. Place chilled patties on the heated surface and cook for about 5-6 minutes per side until golden-brown and internal temperature reaches 165°F.

Remove patties from heat and let rest for 3-4 minutes before serving on whole grain buns or atop a fresh salad.