Preheat your oven to 425°F. While the oven heats, dice the chicken into 1/2-inch cubes, chop the celery into small pieces, mince the onion, and slice the green onions for garnish. Toast the slivered almonds in a dry skillet over medium heat for 2-3 minutes, stirring occasionally, until fragrant and golden—this brings out their deep nutty flavor and prevents them from becoming soft in the casserole.

In a large bowl, combine the diced chicken, celery, minced onion, mayonnaise, toasted almonds from Step 1, lemon juice, salt, and garlic powder. Mix until everything is evenly coated and well combined. The mayonnaise will act as the creamy binder that holds everything together. Reserve 3/4 cup of the Monterey Jack cheese and set the crushed potato chips aside—these will be your crispy topping.

Grease a 9x13-inch baking dish lightly with butter or cooking spray. Pour the chicken salad mixture from Step 2 into the prepared dish and spread it into an even layer. I like to use the reserved cheese and chips as your toppings—sprinkle the 3/4 cup Monterey Jack cheese evenly over the casserole, then top with the crushed potato chips. The chips will create a delightfully crunchy crust as they toast, so crush them into small pieces rather than fine crumbs for maximum texture.

Bake the casserole in the preheated 425°F oven for 20 minutes, until the top is golden brown and the edges are bubbling. The cheese will melt into the chicken salad while the potato chips toast on top, creating a wonderful contrast of creamy and crunchy textures.

Remove the casserole from the oven and let it rest for 2-3 minutes. Garnish generously with the sliced green onions from Step 1, which adds a fresh, bright note to balance the richness of the mayonnaise and cheese. Serve warm and enjoy the combination of creamy chicken salad, melted cheese, and crispy potato chip topping.