How to Make It
In a large bowl, whisk together the lime juice, chile paste, yellow onion and salt. Set aside.
Soak the red onion in a small bowl of cold water for 5 minutes. Drain well.
Meanwhile, steam the sweet potato on a steamer rack set over boiling water, covered, until tender, 5 to 7 minutes. Drain well and set aside to cool.
Cook the ear of corn in a pot of boiling water until crisp-tender, 3 to 5 minutes. Transfer to a platter. When cool enough to handle, cut the kernels from the cob.
Stir the fish into lime juice mixture, along with the red onion, cooled sweet potatoes, corn and cilantro. Stir to combine. Refrigerate for at least 30 minutes before serving.