Preparation

• Bring a large pot of well-salted water to a boil. In a small saucepan over low heat, combine 1 Tbs. of the oil with the shallots, sugar, tamarind, fish sauce, garlic, and sambal oelek. Stir frequently until the sugar dissolves, about 5 minutes. Remove from the heat, and stir in the lime juice and lemongrass. Set aside.
• Blanch the snap peas in the boiling water until bright green and crisp-tender, about 1 minute. Transfer with a slotted spoon to a mesh strainer, and run under cold water until completely cool. Reserve the boiling water. Cut the snap peas in half crosswise on the bias, transfer to a medium bowl, and toss with 3 Tbs. of the tamarind marinade.
• Carefully drop the noodles in small amounts into the boiling water, and cook, stirring continuously to prevent the noodles from sticking, until al dente. Drain the noodles, and run under cold water until completely cool. Transfer to the bowl with the snap peas, and toss well. Set aside.
• Cut the tofu into 1-inch cubes, and toss gently with 1/2 tsp. salt in a small bowl. Heat 2 Tbs. of the oil in a large nonstick skillet over medium heat. When the oil shimmers, add the tofu in an even layer, turning occasionally, until lightly browned all over, about 5 minutes. Drain on a plate lined with paper towels. Add the remaining 1 Tbs. oil to the skillet. When the oil shimmers, add the shrimp and sprinkle with 1/2 tsp. salt. Cook, tossing occasionally, until opaque and cooked through, about 3 minutes. Add the noodle mixture, tofu, 2 Tbs. of the marinade, and 1/2 tsp. salt to the skillet, and toss until just heated through, about
  2 minutes. Remove from the heat, and stir in the basil and scallions.
• Transfer the pad thai to a serving platter, add more marinade to taste, top with the peanuts, and serve with the lime wedges, if you like. Serve any remaining marinade on the side.