Preheat oven to 180°C (350°F).

Heat olive oil in a large oven-safe pan over medium heat. Add diced lamb and brown on all sides. Remove lamb and set aside.

Add chopped onion to the same pan and sauté until softened, about 5 minutes. Add minced garlic and cook for 1 minute more.

Return lamb to the pan. Stir in artichoke hearts, chopped rosemary, salt, and pepper.

Arrange thinly sliced potatoes over the lamb and artichoke mixture in an even layer.

Pour vegetable broth over the potatoes. Sprinkle grated Parmesan cheese evenly over the top.

Cover the pan with a lid or aluminum foil and bake for 45 minutes.

Remove lid/foil and bake for an additional 15 minutes, or until potatoes are tender and the top is golden brown.

Let the gratin rest for 5 minutes before serving.

Serve hot, perhaps with a simple green salad.