Make Luke's special seasoning: In a small bowl, combine all the seasoning ingredients. Set aside.
Make the grilled cheese: In a 12-inch nonstick skillet, heat the butter over medium heat. Place the pieces of bread next to each other, pushing them around the pan lightly to evenly coat them with butter.
Top each piece of bread with 1½ slices of the Gruyère cheese and sprinkle one slice with the pinch of Luke's special seasoning, then cover the pan and cook until the bread is golden and the cheese is melted, 3 to 4 minutes.
Remove the lid and spread the lobster meat over the melted cheese on one piece of the toasted bread. Flip the other on top to sandwich and make the grill cheese. Let cook until the lobster is warmed through, 1 minute more.