We came across this place during a day tour of Riga. It was slightly intimidating to enter - self-service, no English spoke by staff, and it is not clear what you do after you enter. It's cafeteria style. I found another customer with whom I could communicate and asked her what you do, and she basically told me to take what I wanted, and ask for a drink at the end from the cashier.
We grabbed a couple of meat pancakes and a couple of dessert pancakes, some jam, some sour cream, and a couple of bottles of water. Total price was maybe 5 or 6 dollars US per person. The food was great and we had the feeling we had really stumbled across something special. I think we were the only tourists in there.
Very highly recommended for lunch if you don't want a fancy restaurant meal and you want something the locals enjoy.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.