Preheat your Blackstone Griddle over medium high heat to 400 degrees Fahrenheit.
Stir together the Italian seasoning, garlic powder, paprika, salt and pepper.
Season both sides of the salmon filets with this seasoning mixture.
Once the griddle grill has reached 400 degrees Fahrenheit, drizzle the avocado oil onto the grill.
Place the salmon filets on the griddle.
Cook for 4-6 minutes. Then flip the fish and cook for 4-6 more minutes until the salmon reaches an internal temperature for 145 degrees Fahrenheit.
Remove the salmon from the griddle to a separate plate. Squeeze the lemon juice on top of the salmon filets.
Butter the brioche buns and place them on the grill for 1-2 minutes to brown them slightly.
Spread the tartar sauce onto one side of the butter. Top with a butter lettuce leaf and a salmon filet.
Then the sandwiches are ready to serve and enjoy!