There have been quite a few reviews of Tati, not least the recent comparison of three bistros: http://chowhound.chow.com/topics/590799.
Nevertheless a quick review of their prix fixe menu follows:
The prix fixe menu is $25.00 and is offered Sunday to Wednesday. In our view it represented overall good value, given that Winterlicious is a damp squib.
The items on the menu are very simple: soup/salad; bavette frites/poulet frites/a daily vegetarian pasta dish; and apple tart/profiterole for dessert. The salad was straightforward, crisp, and fresh, while the ginger carrot soup arrived piping hot and was delicious. The bavette was perfectly cooked to medium-rare, tasty, and suitably tough. The vegetarian pasta on this night was a fresh beet and tarragon rissotto whose flavours blended uniquely and wonderfully. Desserts were first-rate.
The service was extremely friendly and accomodated complicated dietary restrictions. Admittedly the restaurant was only half full but all the tables seemed to have received appropriate friendly attention.
If you would like to experience this otherwise somewhat more expensive restaurant, the prix fixe, at $25.00, provides good pyrotechnics.