Step 1

Set your pressure cooker to the sauté setting.

Step 2

When the pressure cooker is hot, add 3 tablespoons of the butter and melt for 5 minutes.

Step 3

Add the onion, the celery, and the mushrooms to the melted butter and cook until softened, about 5 minutes.

Step 4

Add 1/2 teaspoon of the garlic powder, 1/2 teaspoon of the kosher salt, 1/2 teaspoon of the black pepper, 1/2 teaspoon of the poultry seasoning, and 1/2 teaspoon of the Italian seasoning and stir well to combine.

Step 5

Add the broth to the pressure cooker and scrape the bottom of the pot with a wooden spoon to release the browned bits.

Step 6

Turn off the pressure cooker.

Step 7

Break the spaghetti in half and lay it in a crisscross pattern on top of the veggies and the broth in the pressure cooker.

Step 8

Cut the chicken into bite-size pieces.

Step 9

Sprinkle the chicken with the remaining garlic powder, 1/2 teaspoon of the salt, 1/2 teaspoon of the black pepper, the remaining poultry seasoning, and the remaining Italian seasoning.

Step 10

Lay the chicken evenly on top of the spaghetti in the pressure cooker.

Step 11

Cover the pressure cooker and secure the lid, making sure the valve is set to sealing.

Step 12

Set the pressure cooker to 3 minutes on manual.

Step 13

When the cooking time is up, let the pot sit undisturbed for 5-10 minutes.

Step 14

Carefully move the valve to venting.

Step 15

When the steam has finished releasing, remove the lid.

Step 16

In a bowl, add the sour cream and the cornstarch and stir well to combine.

Step 17

Add the sour cream mixture and the heavy cream to the pressure cooker and stir to combine.

Step 18

Add the mozzarella and the parmesan to the pot and stir to combine.

Step 19

Season the mixture with the extra salt and the extra pepper as needed.

Step 20

In a small skillet over medium heat, melt the remaining butter.

Step 21

In a small bowl, add the cornflakes and the melted butter and stir to combine.

Step 22

Sprinkle the cornflake topping over top of the spaghetti.

Step 23

Optionally, you can air fry the cornflake topping until browned, about 2 minutes, prior to adding it to the pasta.

Step 24

Serve.