Soak the rice vermicelli in plenty of hot water until softened, 10 to 15 minutes.

Drain the noodles well and roughly chop them with a knife or kitchen shears to make them easier to stir and eat.

Heat the oil in a wok or large saucepan over medium-high heat. Add the urad dal and cook until fragrant and just starting to turn light brown, about 1 minute.

Add the mustard seeds and asafetida, heating until the seeds crackle and pop, which takes about 30 seconds.

Reduce the heat to medium, add the curry leaves and green chili, and cook for 30 seconds—covering the pan briefly can help contain any spattering oil.

Add the corn and cook for 3 to 4 minutes, stirring frequently until tender.

Add the noodles, turmeric, and salt, stirring until everything is fully combined and the noodles are heated through, about 2 minutes.

Remove from the heat and stir in the lime juice, cilantro, and cashews, then serve immediately while warm with lime wedges.