Preheat the oven to 220°C.
Slice the tops off the rolls and remove the bread inside to form hollows.
Melt 55g of butter and brush it onto the lids and the inside and outside of the rolls.
Bake the loaves and lids on a baking sheet for 10 minutes until lightly browned.
Clean and open the oysters, reserving the liquor.
Heat the remaining 55g of butter in a pan and sauté oysters for 1 minute.
Remove the oysters, cut them into three pieces, and set aside.
Combine the liquor, cream, salt, pepper, nutmeg, and lemon juice in the pan.
Boil the mixture steadily while stirring until a thick sauce forms.
Return the oysters to the sauce to reheat and spoon into the warm rolls.