Preheat waffle iron

In a medium bowl, whisk together flour, salt, baking powder and sugar. Set aside.

In a small bowl, whisk together milk, butter, and eggs.

Stir wet ingredients into flour mixture until fully combined.

Spoon batter into waffle iron and cook until done (mine has an indicator light that says when the waffle is ready). Repeat with remaining batter.

Heat a skillet over medium high heat. Butter the outside of two waffle halves.

Place one half, butter side down in the hot skillet. Top with 1/2 of the cheese, chicken, arugula and remaining cheese. Top with other waffle half.

Place grill press on top of the sandwich to ensure even cooking. Cook for about 3 minutes on each side or until waffle becomes crispy and cheese melts. Flip halfway through.