Slice ½ of an onion into ¼" slices and place in the bottom of the inner pot. Cut bacon strips in half. Cook 4 slices of thick-cut applewood smoked bacon in the Ninja Foodi. Place the rack in the high position and lay the bacon down in a single layer and air crisp on 360º F for 14-18 minutes, flipping at 7 minutes. Drain cooked bacon on paper towels.
Turn the sear/saute on high. Deglaze the hot pot with 3 cups of chicken stock or water. Make sure to scrape the bottom of the pot with a non-stick safe utensil.
Add in 8 ounces of Cellentani pasta or your pasta of choice. Make sure to adjust your time depending on which pasta shape you use. See post for more details.
Add 2 Tbsp of flour and 2 Tbsp of melted butter in a pressure safe pan, stir to combine and cover. Place rack in the high position over the pasta and place the pan on top. Put on the pressure lid and make sure to turn the valve to seal. Pressure Cook on high for 8 minutes. Allow to natural release for 2 minutes and manually release the remaining pressure. Add the roux from the pan into the pasta and broth and stir.
Add in 1 cup of half & half or whole milk. Turn the sear/saute on medium. Add in 3 cups of cheese and stir until melted.
Crumble 6 (half) pieces of bacon into mac and cheese and stir. Reserve 2 (half) pieces of bacon for garnish or if you aren't topping with cheese, add in all of the bacon.
Top the bacon mac and cheese with a little more cheese of your choice and the 2 remaining pieces of bacon crumbled. Broil with the TenderCrisp lid for 5-10 minutes or until the cheese has melted and starts to brown. Sprinkle with a little Chipotle powder for a kick. Serve & Enjoy!