First, they allow you to choose any entree from the lunch menu. Hooray! That's about 10 items ranging from $13 (steamed vegetables) to $18 (nut and spice crusted halibut fillet on Chinese eggplant and onions) In between are choices such as ahi tuna, whole catfish, red Thai curry shrimp, steak, and salmon.
The appetizer choices are limited to their house salad (normally $7), pork and shrimp spring rolls ($9), and a lemongrass fish chowder (not on the menu, I'd guess it was ~$8)
Desserts are limited to bittersweet chocolate torte topped with ginger ice cream, or a bread pudding topped with baked pineapple and a coconut creme glaze. The woman at the table next to me asked if there were any more options and the waiter said he'd ask the kitchen if she could have a trio of sorbets.
I chose the spring rolls (generous serving and excellent, even the 3 dipping sauces), halibut (wonderful), and bread pudding.
My only quibble, minor: the dessert serving size was a bit small (but still delish).
As a bonus, I was given a dish of endamame to nibble on, a hot damp towel to wipe my hands, and 2 small coconut patties when they gave me the check.
Service was very good, never too intrusive and luckily never sloppy or neglectful. The waiter made sure all his tables knew about the RW special, he said himself he felt it was a bargain, and I never felt I was "underserved" or "downgraded" because I ordered it. It's an attractive restaurant (and mostly full and busy even at 2pm).
Considering the regular menu prices, I thought the RW deal was a bargain. A la carte for those items, I would have paid $35 (before tax/tip).
So hie thee to Ten Penh!