Prepare chicken nuggets according to package directions. Make sure they are golden brown and crispy, and that the internal temperature has reached 165°F.
Add potatoes to a pot of salted water. You want enough water to just cover the potatoes, and the water should taste very salty. Bring potatoes to a boil, and cook for 15 minutes until fork tender, then drain.
Now, mash the potatoes using a potato masher, stand mixer, blender, or hand mixer. Add potatoes, 8 tablespoons of melted butter, heavy cream, about 1 tablespoon of salt, ¼ teaspoon of pepper, ½ teaspoon of onion powder, and ½ a teaspoon of garlic powder and mash until creamy and smooth.
To make the gravy, melt the remaining 4 tablespoons of butter in a sauce pan. Gently pour in chicken stock, and season with remaining salt, pepper, onion powder, and garlic powder. Slowly whisk in the xanthan gum, whisking constantly to dissolve it. Bring to a boil, then reduce to a simmer, whisking often until desired texture is reached.
In single-serving bowls, layer mashed potatoes, chicken, corn, gravy, and cheese. Garnish with parsley if desired. Serve and enjoy!
Store leftovers in separate airtight containers in the fridge for up to 5 days. Reheat and assemble!