In a medium bowl, combine the ground turkey, 1/4 c. of the feta cheese, diced roasted red peppers, 1 tsp of pesto, garlic powder, salt and pepper. Divide mixture evenly and form 4 patties.
Heat a large skillet over med-high heat and drizzle with olive oil. Place burgers in heated skillet, turn down to medium and cover. Cook for about 5 minutes before flipping, covering will help steam and cook quicker. Flip and cook for an additional 5 minutes or until burgers are cooked all the way through. Top with remaining feta cheese and cover to melt.
While burgers are cooking, combine the Greek yogurt pesto spread ingredients and set aside.
Assemble burgers with Greek spread, tomatoes, lettuce, and your burger, enjoy!
These would also be good on the grill if you are able to use a non-stick grilling spray to avoid sticking and crumbling.