In a large bowl, combine minced lamb, bread crumbs, finely chopped onions, chopped fresh herbs (mint, rosemary, thyme), egg, and apple juice. Season with salt and black pepper to taste, and mix well.
Form the mixture into 4 equal cutlets.
Heat vegetable oil in a large skillet over medium-high heat. Place the cutlets in the preheated pan and fry for 3-4 minutes on each side, until the internal temperature reaches 71°C / 160°F.
Place a couple of lettuce leaves and one cutlet on each burger bun base. Cover with the top bun half.