Slice each lamb fry in half lengthwise, and remove from the membrane; set aside.
Heat the vegetable oil in a large skillet over medium-high heat. Stir in the lamb fries, and cook for about a minute until they begin to firm and change color. Stir in the Armenian peppers, onion, spinach, and butter. Season with lemon juice, lemon pepper, and salt. Cook and stir until the lamb fries are firm and white in the center, and the liquid from the vegetables has cooked down, 15 to 20 minutes.