Chop the peeled onion into small pieces. Peel the figs, put half a fig aside, chop the rest coarsely.
Melt the butter in a saucepan, add the onion cubes until translucent, add the figs while stirring and simmer for about 1 minute.
Add the green pepper and the clear soup and blend in a hand mixer until smooth. Pour back into the saucepan, season with the juice of one lemon and sherry, bring to the boil and thicken with the whipped cream whisked with the egg yolk.
Keep warm, but do not let it bubble up. Cut the reserved half fig into slices. Serve the soup in cups, with fig slices and green peppercorns.
Notes from Franz Betzel:
The fig tree is nowadays cultivated mainly in Turkey, Italy, Spain and Greece. The ripe figs are rich in glucose, they are dried and sold in wreaths or pressed. Fresh figs quickly become moldy, but they have nevertheless been equally available in our markets for some time.
Green pepper is actually nothing more than unripe black pepper. Normally, the berries are dried in the sun and fermented in the night dew, becoming black and wrinkled. Green pepper, on the other hand, is preserved unfermented in a salt solution. It is used mainly in the manufacture of sausages and pepper steaks and salads.