Turkey Feta Meatballs

Name: Turkey Feta Meatballs
Ingredients: 1 lb. ground lean turkey; 1/2 small yellow onion, finely chopped; 1 large egg, lightly beaten; 4 cloves garlic, minced; 1/2 c. panko bread crumbs; 2 tbsp. chopped fresh parsley; 1 tbsp. chopped fresh dill; 1 1/2 tsp. kosher salt; Freshly ground black pepper; Pinch of red pepper flakes; 1/2 c. crumbled feta (about 3 oz.); Extra-virgin olive oil, for greasing; 1/2 c. Greek yogurt (preferably full-fat); Juice of 1/2 lemon; Kosher salt; Lemon wedges and chopped fresh dill and parsley, for serving