Spinach-Feta Turkey Burgers

It's been awhile since I've posted anything; mainly because I've been busy or haven't been cooking anything new. Although, lately it's because I've been sick with some sort of plague. I think this is was last new recipe that I had tried, and it was probably a good two weeks ago. I don't have a photo, but these turkey burgers turned out pretty great. I would consider these my favorite turkey burgers to date; or at least in the top three. There is no real "source" for these bad boys; just something I threw together 'off-the-cuff' one night. I just wanted to warn you that the measurements are not exact, as I totally improvised. We had company over on this occasion, so it made a lot of burgers...you could probably cut the recipe in half for a normal "family" sized meal not fit to feed an army.

Spinach-Feta Turkey Burgers

Ingredients:
olive oil
2 (1.25 lbs.) of lean ground turkey
2 onions, diced
1 large package of baby spinach (or 2 bags of salad-sized bag...my large container was from Costco)
4 cloves of minced garlic
1 tablespoon of dried oregano
1 tablespoon of Greek seasoning (I use Cavander's)
salt and pepper to taste
1 egg, beaten
1/2 cup of Panko bread crumbs, more if needed
1 (8 oz.) container of feta cheese
hamburger buns
cooking spray
mayo, for burger condiment

Directions:
Preheat oven to 350 degrees.

In a large skillet over medium-high heat, saute onions in 2 Tablespoons of olive oil. When onions are soft and starting to caramelized, add garlic and spinach. Stir until spinach is wilted and cooked and garlic becomes fragrant. Add salt and pepper to taste. Remove spinach mixture to a large bowl to cool for 5-10 minutes. Once mixture has cooled, add ground turkey, egg, feta, bread crumbs, Greek seasoning, oregano, and additional salt and pepper to taste. Mix well with your clean hands, to make sure all the ingredients are well combined. If meat mixture feels to "wet", add more breadcrumbs 1/4 cup at a time until you are satisfied with the consistency. Form into burger patties and set aside. Heat indoor grill pan, prepared with cooking spray, over medium high heat. Cook burgers until browned on both sides, flipping once, but not thoroughly cooked in the middle. Remove undercooked burgers to a lined half sheet pan (I used a Silpat mat) and finish cooking thoroughly in the preheated oven; about 15-20 more minutes or until no longer pink in the center. Let burgers rest for 5 minutes before serving on hamburger buns, topped with a bit of mayo for garnish.