Place 1 kg minced meat in a large bowl. Add the marinade, 1 egg, 6 tablespoons breadcrumbs, and the chopped parsley. Knead everything together well. Refrigerate for at least 2 hours before cooking.
Divide the mixture into 5 portions of 200g each. Shape each portion into a disc approximately 15 cm in diameter. Place 1 slice of feta cheese on one half, fold the other half over it, and press the edges lightly to seal.
Cook on a grill or in a pan over medium-high heat for 4-5 minutes per side until the internal temperature reaches 71°C (160°F), approximately 8-10 minutes total. Alternatively, bake in an oven preheated to 200°C (400°F) for 12-15 minutes until the internal temperature reaches 71°C (160°F).