Preheat your oven to 350°F (175°C).
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and garlic, and sauté until soft and translucent.
Add the lamb chunks and cook until browned on all sides. Season with salt and pepper. Remove from heat and set aside.
In a small pot, bring 1 cup of water to a boil. Add the rice and a pinch of salt. Reduce the heat, cover, and simmer until the rice is cooked, about 15 minutes. Remove from heat and set aside.
In a large mixing bowl, whisk together the Greek yogurt, eggs, flour, dried oregano, dried mint, and a pinch of salt. Mix until smooth.
In a large baking dish, spread the cooked rice in an even layer. Place the browned lamb chunks on top of the rice.
Pour the yogurt mixture over the lamb and rice, spreading it evenly.
Dot the top with small pieces of butter.
Bake in the preheated oven for about 45-50 minutes, or until the top is golden brown and the mixture is set.
Allow the Tavë Kosi to cool slightly before serving. Garnish with freshly chopped parsley.
Enjoy your meal!