Preheat oven to 375°F. Grease a 2-quart baking dish; set aside.
In a dry skillet, toast almonds over low heat just until fragrant and golden brown. Stir frequently, and keep a close eye on them, because the nuts can burn quickly. Transfer toasted almonds to a plate.
In the same skillet, heat olive oil over medium heat. When the oil shimmers, add the celery and onion. Cook, stirring frequently, until the onion is translucent, about 5-7 minutes. Add the garlic and cook until fragrant, about 30 seconds.
In a large bowl, stir together the almonds, onion, celery, garlic, chicken, salt, and pepper.
In a medium bowl, stir together ½ cup of the cheddar cheese, mayonnaise, sour cream, lemon juice, and chives.
Add the mayonnaise mixture to the chicken mixture; stir to combine. Taste and season with additional salt and pepper, if necessary.
Transfer to the prepared baking dish. Sprinkle with the remaining ½ cup of cheddar cheese and the crushed potato chips.
Bake, uncovered, until the cheese melts and the filling is hot, about 20 minutes.
Garnish with fresh parsley or sliced scallions and serve.