Put 700g of the dry macaroni in the pressure cooker bowl, followed by 2L of water.
Stir it before closing the lid and setting the pressure release valve to the “SEAL” position.
Select the “PRESSURE” function and set off at low for 0 minutes.
At the end of the pressure cooking, leave the pressure to naturally release for 14 minutes before doing a quick release by carefully moving the valve to “VENT.”
Once the pressure has fully released remove the lid. Add the remaining ingredients, except the bread crumbs and butter, to the pot. Stir in the 480ml of double cream, 2 tsp salt, 1 tsp pepper, 1.5 tsp each of onion powder and garlic powder, 1 tbsp mustard (or 1 tsp mustard powder) and 720g grated Cheddar cheese. Stir everything together until the cheese has melted.
Melt the 230g butter and mix it with the 200g of bread crumbs.
Cover the macaroni with the bread crumb mixture.
Set the Ninja Foodi (or different multi-cooker) to the “AIR CRISP” mode and set the temperature to 180°C and the timer to 7 minutes.
At the end of the air crisping time the macaroni cheese will be a golden brown, baked and ready to enjoy!