In a medium bowl, combine lime juice, soy sauce, sugar, and garlic and use a fork to whisk in the toasted sesame oil. Taste and adjust flavors as needed; dressing should taste zingy and highly-flavored. Set aside.
Prepare the rice noodles according to package directions. Drain and rinse, then toss with some toasted sesame oil in a bowl to prevent sticking. Continue to toss occasionally to keep the noodle strands from clumping together.
Add vegetable oil to a large skillet over medium heat, swirling pan to coat the entire surface. Heat oil until slightly smoking. Arrange mandu in skillet and fry until golden brown, about 2 minutes. Turn over and fry on the other side for another 2 minutes. Remove mandus from pan and let rest on a plate lined with paper towels.
Pour the dressing over the rice noodles and toss to coat. Divide noodles among bowls and garnish with vegetables, herbs and fried mandus and serve.