Heat a dry skillet over medium heat. Add sliced almonds and toast, stirring frequently, until golden and fragrant, about 3 minutes. Transfer to a plate to cool.
In the same skillet, add corn kernels. Cook without stirring for 2 minutes, then stir and cook until charred in spots, about 2 more minutes. Transfer to a plate to cool completely.
In a large bowl, scoop the avocado flesh and mash with a fork to your desired consistency—leave some chunks for texture. Stir in lime juice, salt, pepper, and cayenne if using.
Add the shredded chicken, toasted almonds, cooled corn, red onion, and cilantro to the bowl. Fold gently until everything is evenly coated.
Taste and adjust seasoning with more salt, lime juice, or cayenne as needed. Serve immediately, or cover and refrigerate for 30 minutes to let flavors meld.