Soak the plums in the Calvados. Rinse and dry top leg of turkey Rub with salt and pepper. Heat oil in a small cast iron roasting pan. Sear turkey top leg on skin side until golden, turn to other side and brown. Lift leg out of fat. Fry celery in 1 cm thick slices, celery and carrots in 1×1 cm cubes, small peeled whole shallots and the garlic clove in the fat until they have taken on a slight color. Later put the leg on top with the skin side up and extinguish everything together with cider. The cider should not cover the leg but only offer up to half. Put the roaster in the heated stove at gas level 2 and steam for 1 hour. Check now and then if there is still liquid, add cider once more.
Celery-peanut puree:
20 min before end of roasting, peel and halve potatoes and peel and chop 1/2 celery bulb in a little salted water. Cook for 20 minutes. When the potatoes are soft, drain. Steam carefully. While still hot, squeeze the potatoes and celery through a potato ricer, add hot milk and butter, stirring until the mash has a loose, light consistency, season with salt and a pinch of nutmeg.
Apple garnish:
In the meantime, cut out apple cores, remove peel from apples and cut into eighths. Cut butter into e