Step 1

Preheat the oven to 375 degrees F.

Step 2

In a 12-inch skillet over medium heat, cook the bacon strips, stirring often, until they are crispy, about 8 minutes.

Step 3

Transfer the bacon from the pan with a slotted spoon to a paper-towel-lined plate. Leave the drippings in the skillet.

Step 4

Add the onion and the garlic to the drippings in the skillet and cook, stirring often, until they have slightly softened, about 5 minutes.

Step 5

Whisk the cream cheese, the milk, the ranch seasoning, and 1 cup of the cheese into the onion mixture until it is smooth. Transfer it away from heat.

Step 6

In a large bowl, combine the ranch mixture, the cooked pasta, the cooked chicken, the pimientos, and 1/2 cup of the green onion.

Step 7

Transfer the mixture to a 13x9-inch casserole dish.

Step 8

Sprinkle the bacon evenly over the casserole and top with the remaining cheese.

Step 9

Bake the casserole, covered, until the top is golden-brown and crispy, about 25-30 minutes.

Step 10

Let the casserole cool slightly.

Step 11

Garnish the casserole with the remaining green onion and serve.