Pat salmon dry with a paper towel and season with Cajun seasoning and set aside.
Slice onion, red and green peppers lengthwise and set aside.
In a medium pan on high heat, add cooking oil and sear salmon on both sides for 3-4 minutes until partially cooked through.
In the same pan, add veggies and cook until soft and translucent.
While veggies are cooking, add salmon back to the pan and begin breaking salmon down into bite-sized pieces (similar to the technique used for preparing cheesesteaks) and blending all ingredients together.
While meat mixture cooks, toast hoagie rolls in a separate pan with a little butter.
When salmon and veggies are cooked through, separate mixture into even sections based on number of hoagies you'll serve. Add slices of provolone over each divided section.
To the pan, add about 1 tablespoon of water and as smoke releases, cover the pan for 1-2 minutes until cheese fully melts.
Place melted, cheesy meat mixture into toasted hoagie rolls and evenly spread creamy remoulade sauce on one side of the hoagie roll.
Repeat these steps for remaining salmon cheesesteaks and enjoy!