In a medium saucepan, combine soy sauce, fish sauce, lime juice, and sugar over medium heat. Stir for 2-3 minutes until sugar dissolves and mixture thickens slightly. Set aside to cool.

Bring a large pot of water to a boil. Add the rice noodles and cook according to package instructions (about 5-7 minutes). Drain and rinse noodles under cold water to stop cooking. Toss with oil to prevent sticking.

While the noodles cool, prepare your chosen protein. Cook chicken, beef, or shrimp (grill or sauté for 5-6 minutes until cooked). For tofu, marinate and cook until crispy, about 3-4 minutes per side.

Wash and prep vegetables and herbs: julienne or shred carrots, slice cucumber into strips, tear lettuce. Chop cilantro, Thai basil, and mint.

In a large mixing bowl, combine cooled rice noodles, dressing, and proteins. Gently toss to coat, then add vegetables and herbs, mixing until evenly distributed.

Serve immediately in a large platter or individual bowls. Top with garnishes like fried shallots, crushed peanuts, and lime wedges. Add sliced red chilies for heat if desired.