Cook macaroni according to package directions.
Meanwhile, in a Dutch oven, melt butter over medium heat.
Add flour. Stir and cook for 1 minute.
Gradually whisk in milk. Bring to a simmer. Add salt, pepper, garlic powder, onion powder, and dry mustard.
Once thickened, turn heat to low and add cream cheese. Stir until melted.
Add Monterey Jack cheese and cheddar cheese. Stir until melted.
Stir in sour cream and hot sauce.
Stir in macaroni, chicken and blue cheese. Sprinkle with green onions.