Bring the milk to the boil with a pinch of salt, add the washed rice pudding and let it soak over a low heat for 30 minutes.
Drain the peaches on a colander. Bring the peach juice with the lemon juice to the boil and remove from the hotplate. Stir the cornstarch with a little cold water until smooth, bind the peach juice with it, bring to the boil again and refrigerate.
Beat the butter with the whole beaten eggs and the sugar until frothy. Add the grated zest of the lemon and mix in the finished, cooled rice pudding.
Pour half of this mixture into a well-greased casserole dish, spread 3/4 of the peach slices on it, pour the remaining rice mixture over it and put flakes of fat on top.
Bake the casserole in the oven at approx. 200 ° C until golden brown. Garnish with the remaining peach slices and serve hot with the well-chilled peach juice.