In a mixing bowl, stir together the ground turkey, bread crumbs, Parmesan, Italian seasoning, garlic powder, milk and egg until well combined. Remove the mixture to a clean dry surface (like a cutting board) and separate into 12 equally-sized piles. Place a string cheese chunk into the center of each meat pile and roll the meat into a ball surrounding the cheese.
Place the oil in a large skillet or saute pan and bring over medium-high heat. When heated, add the meatballs and cook, stirring/flipping when needed, for 5-6 minutes until all the sides of the meatballs are browned. Don’t worry if the inside isn’t cooked through all the way, they’re going in the oven! Remove from heat and allow meatballs to cool so they can be handled.
Pre-heat the oven to 400. Line a baking sheet with parchment paper and set aside.
While the meatballs are cooling, combine the self-rising flour and the Greek yogurt in a mixing bowl and stir with a fork until combined. Sprinkle a bit of flour on a cutting mat and transfer the dough to the floured workspace. Knead the dough 8-10 times on the floured surface. Dough should be slightly tacky but not wet or overly sticky. Use a rolling pin to roll out the dough into a large rectangle (about 10”x14”). Use a pizza cutter or knife to cut the flattened dough into 12 equal squares.
Place a meatball on the center of each dough square and then fold the corners of the dough up over the meatball. Seal the edges and roll a bit to form a dough ball around the outside of the meatball. You may need to add flour to your hands a few times while you do this to prevent the dough from sticking.
Place the dough-wrapped meatballs onto the prepared baking sheet and use a pastry brush to coat them with the beaten egg white. Sprinkle the tops with a bit of extra Italian seasoning or oregano and place in the oven for 20-22 minutes. I recommend serving these warm with your favorite marinara, pizza or pasta sauce for dipping!