Macvin du Jura is a liqueur made by blending vineyard grape juice (fermented or not) with Marc du Jura eau-de-vie. The resulting mixture is left to mature for at least a year in barrels before bottling. This makes a very intense, sweet liqueur with a unique and delicious flavour.
By "mash powder" do you mean mash potato powder?
If so, yes you can, see how to on this chicken recipe : chicken breasts in a potato crust.
Can I use potentiometer mash powder to make cutlets?