For the rolls, stir yeast with sugar until liquid. Heat the fat and milk. Add 60 ml water and cool lukewarm. Put 1/2 tsp salt, flour and 1 egg in a bowl. Add the milk mixture and immediately knead into an elastic dough with the dough hooks of the hand mixer for 6-8 minutes.
Cover and leave to rise in a warm place for about 45 minutes.
Knead the dough again briefly on a floured work surface. Form approx. 24 small round rolls from the dough. Put them on two baking trays lined with baking paper, cover and let them rise for another 20 minutes.
Whisk the egg yolk and cream. Spread the bread roll with it, sprinkle with sesame seeds. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) one after the other for 15-18 minutes.
Take out and let cool on a cake rack.
Soak toast in cold water. Peel onion and dice very finely. Wash the thyme, shake dry and pluck the leaves from the stalks. Squeeze the bread. Put minced meat, onion, 1 egg, bread, mustard, thyme, 1 teaspoon salt and 1/2 teaspoon pepper in a mixing bowl and knead well.
Form approx. 24 small, very flat meatballs (approx. 6.5 cm Ø) from the mixture with moistened hands. Heat the oil in 2 portions in a large frying pan, fry the meatballs in these portions over medium heat for approx. 4 minutes while turning.
Remove and place on a baking tray lined with baking paper.
Quarter cheese slices. Cover each meatball with a piece of cheese and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 3-4 minutes, remove from oven. In the meantime clean, wash and drain the salad.
Wash and slice the tomatoes. Drain the gherkins and cut in half lengthwise.
Cut open the bread roll, cover the lower halves with lettuce, meatballs and tomatoes. Spread fig mustard on top, cover. Cover each half with half a cucumber and stick together with a skewer.
Arrange on a plate.