This Thai restaurant stands out from the rest for the simple fact that it has a large, separate vegetarian menu. Only a few other Thai joints in the Bay Area can claim the same (Blue Mango with 2 locations in San Jose, Basil Cha Cha in Foster City, and Green Papaya in Berkeley).
The food here is also just a shade above average, but it's not spectacular by any means.
I had a spicy baby corn with basil ($10), a red curry with soy protein ($10) and an order of brown rice ($2).
The baby corn dish was just your average soy sauce-based stir-fry, but they made it just perfectly spicy (to make you feel it, but not to regret it). The fried tofu in the dish looked limp, though, and there wasn't much of it. In general, the portion size on this dish was small.
The red curry had a hearty taste and was above average. I prefer the curries at Blue Mango (which use higher grade and thicker coconut milk), but this one was decent too. The soy protein in the dish, however, was weird: it was just long flat shreds of white stuff that was sort of firm and sort of soft. In the future, I would just get this dish with tofu, as I didn't care for the texture of the soy protein (it should have been firmer).
Like most Asian restaurants in the Bay, you get charged for rice. At least they had a nice variety of brown rice and they give you a substantial portion, too (not just one of those small cups that most places use).
I am vegan and while I appreciated the separate vegetarian menu, I didn't appreciate the sloppiness of the kitchen, which resulted in one piece of actual chicken in my curry, and one piece of pork in my stir-fry. I'm not super picky about this type of contamination, but it's a sign of laziness; for many vegans and vegetarians, it's simply unacceptable and Siam Taste would do well to clean up its act.
The service was friendly but the restaurant lacks any ambiance. A large tv is mounted up front and it plays random images and news from Thailand, in Thai.
In conclusion, Siam Taste is respectable, but nothing great. I'd rather go to Blue Mango, which is the best Thai food I've had in the Bay Area.