Place a large pot of water on the stove to boil. Let this water come to a boil while you start making the cheese sauce.
In a medium sauce pan, heat oil over medium heat. Add onions. Sauté onions until soft, or about 3 - 4 minutes.
Add the flour to the oil and onions. Stir. It will form a paste. Spread this paste throughout the bottom of the pan and allow the flour to cook for a minute, stirring a couple times.
Grab a whisk. Whisk in evaporated milk and broth. Bring to a boil whisking the whole time to prevent the sauce from sticking to the bottom of the pan and burning. Whisk for 3 - 5 minutes or until sauce is thickened.
Reduce heat to low. Stir in onion and garlic powder, paprika, and salt. Add pumpkin puree and hot sauce. Whisk together well.
Turn off the heat under the pan. Stir in 8 oz of shredded cheese. Make sure to save 2 oz for the topping. Stir gently until cheese is totally melted. Cover.
At this point, your water should be boiling. Cook pasta according to directions on the box. Do not over cook! Over cooked pasta doesn't hold up will to the stirring and sauce addition.
Drain pasta very well. Excess water will make your cheese sauce runny.
In your large pasta pan, add back the cooked pasta. Add chicken. Add cheese sauce. Stir carefully until well combined.
Pour mac-n-cheese into a 9x13 inch pan. Top with 2 oz white cheddar cheese + 1 - 2 oz goat or blue cheese.
Bake in a 375 degree oven for 10 minutes or until bubbly around the edges and cheese is melted. <This is optional if you're in a hurry!>