Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Mulgikapsad (also Mulgi kapsad) is sauerkraut stewed with lard, meat (mostly pork) and pearl barley. It is in the list of the Estonian cultural heritage, and can be considered to be an Estonian national food.
What makes this food unique to Estonia, is added pearl barley, that is not added because of taste, but to inexpensively add a nutritional value and change the visual appearance of the food.