A note on the sauce: Traditionally, bún is served with a sauce called nuoc cham, which includes nuoc mam, or fish sauce. This is a quick vegetarian version using soy sauce. If you want, substitute real fish sauce or vegetarian fish sauce (available at Asian markets) for the soy sauce.
Bún Chay (Vietnamese Vegetarian Noodle Salad)
4 ounces dried rice sticks or vermicelli
1/2 pound extra firm tofu
1 1/2 cups shredded lettuce
1 cup mung bean sprouts
1/2 cup julienned cucumber
Large handful of mixed herbs, coarsely chopped or torn (basil, mint, cilantro; if available: rau răm or Vietnamese coriander, tiá tô or Vietnamese perilla)
2 tablespoons fresh lime juice
2 tablespoons soy sauce
2 tablespoons sugar
4 tablespoons water
1 clove garlic, crushed
2 tablespoons peanuts, chopped
For the noodles
Bring a large pot of water to a boil and add rice sticks. Stir and cook until noodles are white and tender but still firm, about 3-5 minutes. Drain in a colander and rinse under cold water, fluffing the noodles to separate the strands. Drain again completely.
For the tofu
Cut tofu into bite-size pieces and press between clean kitchen towels or paper towels to rid of excess water. Heat oil in a skillet and fry tofu until crispy and golden. Drain excess oil.
For the greens
Prepare the greens and set aside. (May be prepared ahead of time and kept in the refrigerator.)
For the sauce
In a small bowl, whisk together ingredients for sauce. Set aside. (May be prepared ahead of time kept in the refrigerator.)
Divide the noodles between two bowls. Arrange greens and tofu on top and garnish with peanuts. Just before eating, drizzle with sauce to taste and toss.