Mountain View's downtown Castro Street has the good fortune to be bookended by modern Vietnamese restaurants: Xanh at the train station end and Savory up near El Camino Real. The two could hardly be more different.

Xanh is hip, loud and large. Savory seats only 48 people, in a storefront that chef/owners Polly and Janie Tran have transformed into a spa-like oasis, with cool blue walls and soothing background music. Previously, it was a Filipino restaurant with a karaoke stage.

At Savory, diners can get an easy introduction to Vietnamese food. Business meetings and book groups find a good venue.

The Trans are third-generation restaurateurs. Both went to college and had high-tech careers, but they grew up working at their parents' restaurants in San Jose, and always wanted to run their own show. They also learned to cook from their grandmother, who had a restaurant in Saigon.

Specialties include juicy tamarind prawns on a bed of crisp rice noodles ($18) and tender shaking beef ($18). At a steakhouse, you'd pay more, and have to cut it yourself. The cubes of beef go well with fresh spinach and cherry tomatoes. On weekends, the Trans try out intriguing new dishes.

For $12, the lunch combination features the spring roll of your persuasion (fresh, fried, vegetarian), an entree with rice or vermicelli, and an ample green salad with a satisfyingly spicy dressing. If you'd rather go a la carte, it's no problem. Most of the dinner menu also is available at lunch.

Among starters, the tiger prawn mixed green salad ($9) offers four char-grilled prawns, good-sized and sweet. Fresh rolls ($7 with poached shrimp or vegetarian) could use a snappier peanut sauce. Savory's dipping sauces are a weak spot.

The special rice in clay pot, which we tried on the lunch combo, similarly lacked oomph. The chicken was a little dry. There was a lot of ginger in the background, but flavors didn't come together.

However, grilled aubergine ($8) was spectacular. Two Japanese eggplants, peeled but still whole, were utterly creamy, in a chili soy sauce that sweetened when charred. Other vegetarian dishes include mixed vegetables with mushrooms, and lemongrass tofu.

Also excellent, the garlic crab noodles ($15) were redolent of lemongrass, with garlic in the background. Flecked with crab, the airy glass noodles got more satisfying the more you ate.

Among the char-grilled options, I'd take beef over chicken ($12 each). The latter was three very lean boneless thighs that could have used more marinating or a more noticeable dipping sauce. Also thin and lean, pieces of beef were rolled around green onion and then grilled, so you get a taste of both in each bite.

Savory is very strong in the dessert and beverage departments, from refreshing ice tea to a small but well-selected wine list that offers notes about which foods might go with the wine.

For dessert, the fried banana ($7) must be shared. Creamy and hot inside, four good-sized slices are coated in a thin, not puffy, crispy crust. They come with a big scoop of ice cream and shredded fresh coconut. A perfect ending.

Savory

873 Castro St., Mountain View

650-691-9999.

Lunch: Weekdays 11:30 a.m.-2:30 p.m. Dinner: 5-9 p.m. Mon.-Thurs., 5-10 p.m. Fri.-Sat.