Preheat your oven to 375°F (190°C).

In a large bowl, soak the torn bread in cold water for about 20 minutes. Afterward, squeeze out and discard any excess water from the bread.

To the bowl with the soaked bread, add feta, chopped mint, garlic, and 1/2 teaspoon each of salt and pepper. Toss everything to combine.

Gently mix in the ground lamb until just combined; then form the mixture into twelve 2-inch meatballs.

Heat the olive oil in a 12-inch cast-iron skillet over medium-high heat. Add the meatballs, cooking them for about 10 minutes while turning to brown them on two sides.

Once browned, transfer the meatballs to a large plate.

Carefully pour off any excess fat from the skillet, leaving a thin coating. Reduce the heat to medium, then add the onion and cook for around 5 minutes, stirring occasionally.

Next, add the crushed tomatoes, broth, oregano, bay leaves, and an additional 1/4 teaspoon of salt. Stir to combine, heat to a boil on high, and then reduce the heat. Let it simmer for 15 minutes or until slightly reduced, stirring often.

Return the meatballs to the skillet, and top them with shredded mozzarella cheese.

Transfer the skillet to the preheated oven and bake for 20 minutes.

Finally, switch your oven to broil on high and broil for 3 minutes or until the cheese has browned beautifully. Garnish the dish with more mint before serving.