Mr Prata is an Indian/Malaysian restaurant on the Ubud main road. It is a little along from the busy section of Ubud and misses a lot of business because of this.
There are a few Indian restaurants in Ubud, but not many other places to buy paratha. The taste is pretty authentic. It is part of a chain of restaurants.
Since we visited here last year they have done renovations, so your experience may be different from ours.