Rinse artichokes, separate outer leaves and remove stems. Rinse lemons in hot water and slice. In a large saucepan, boil artichokes for 20-25 minutes in salted water.
Drain and rinse with cold water. Cut into quarters and remove the "hay". Peel and dice onion and garlic. Rinse parsley, shake dry and finely chop.
Heat oil. Saute onion and garlic until golden. Stir in lemon zest and parsley. Beat the eggs with milk and season with salt and pepper. Combine with onion mixture and stir in Parmesan.
Grease a baking dish. Pour in eggs and Parmesan mixture and the artichokes. Bake in a preheated oven at 180°C (approximately 350°F) for 30-40 minutes.