Grate cheese. Drain the olives, let them drip off and cut green olives into rings. Whisk eggs, egg yolks, flour, parmesan, milk and cream. Season with salt and pepper. Add green olives. Grease an ovenproof dish (approx. 12 x 12 cm).
Pour in the egg mixture. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 35 minutes.
In the meantime, cut black olives crosswise in half. Clean the rocket, wash and spin dry. Cut sausage into thin slices. Brush a large coated pan with oil. Fry sausage slices in it at medium heat for 3-4 minutes until crispy.
Drain on kitchen paper.
Remove the mould from the oven and let it cool on a cake rack for about 30 minutes. Carefully remove from the mould and cut into 25 cubes. Put the cubes on skewers, each with a slice of sausage and half an olive.
Arrange skewers on a plate and garnish with rocket.