Sprinkle seasoning mix onto both sides of the filet to evenly coat.
Place salmon fillet into the air fryer at 400℉ for 18 minutes, flipping half way through.
While salmon in cooking, prepare toppings.
Slice croissant in half and add cheese in-between.
Once salmon is finished, break into smaller pieces with a fork, then add the salmon inside of the croissant.
Place the sandwich into the air fryer, and toast the sandwich for 3-4 minutes at 350℉. If you want to avoid the croissant getting to crispy, wrap the sandwich in aluminum foil prior to toasting.
Once the cheese has melted, take your salmon croissant sandwich, and add your toppings: arugula and sliced tomatoes.
Serve hot and enjoy or wrap it up and save for later.