Cajun fry seasoning: add all the seasonings to a small bowl and stir to combine.
Store in a sealed container on your counter until time to use.
French fries: do not peel potatoes. Cut fries into plank shapes, about 1/4 inch, by 1/2 inch. Add all your potato slices to a large bowl full of cold water. Allow them to soak for 30 minutes. After the 30 minutes, drain the potato slices and dry them well on paper towels. Attempt to get them as dry as possible.
Add your oil to a large heavy bottomed pot. You need your oil to be at least 3 inches deep in the pot.
Bring the oil temperature up to 275 degrees F (135 C) and fry your potatoes in batches for 5 to 6 minutes. This first stage is to cook the potato all the way through. This isn't going to make your fries turn brown and crispy. That comes in the second fry.
Remove the par-cooked potatoes from the oil to a rack to cool. At this point, you can store them in the fridge for up to 3 days if you don't want to eat them immediately.
Once all of your potatoes have been fried once and you are ready to eat, raise the temperature of your oil to 375 F (190 C).
Once again fry your potatoes in batches until they turn golden brown 4 to 5 minutes.
Move each batch of fries to a bowl or plate and season with the Cajun seasoning immediately while they are still warm.
Once all the fries are fully fried and seasoned, serve and enjoy.