Adjust amounts to fit what you feel like eating.
I know, I know. This is a pointless step that you would rather just skip, but cooking is almost always more fun with a little preperation.
My favorite way is to slice the potato longways in half, then each half along the same plane into three parts. Then rest the potato on the flat side and cut longways on the tangent plane of the first cuts, and finally cut across the cuts you just made.
Lightly oil the potatoes and place them in an air fryer at 380f for 12 minutes. Flip or toss halfway through.
Until the butter is melted and hot.
Slice an onion however you want (dice for a more homogenous result, leave in strips for more a varied tasting experience) and add it to the oil and butter. Let lightly brown, stirring occassionally.
Now is the best time to add any spices you choose to add.
Sprinkle in the flour while stirring to avoid the formation of clumps.
This one is pretty self-explanatory. Work fast after adding the flour.
The amount is mostly up to you, experiment with what works best for your tastes. In general an eighth cup is a good starting point. At this point you can turn off the heat, the cheese should melt into the rest quickly.
After the potatoes are crispy (roughly the 12 minutes mentioned before) add them to the thick cheese sauce.
Putting pickled jalapeños on top will add a great salty, crunchy bite to the dish that goes well with the extremely rich potatoes and cheese.
I do not even want to know...
Potatoes are a fundamental human right, and should be enjoyed as such.