01 -
Spread the softened butter on one side of each slice of sourdough bread. On the unbuttered side, spread a thin layer of mayonnaise for a tangy twist.
02 -
In a bowl, combine the shredded aged cheddar, Gruyère, blue cheese (if using), garlic powder, onion powder, thyme, smoked paprika, salt, and pepper. Mix well to distribute the spices evenly.
03 -
Place two slices of bread, mayo side up, on a clean surface. Generously heap the cheese mixture onto one slice of bread, then place the other slice on top, mayo side down. Repeat for the second sandwich.
04 -
Heat a non-stick skillet or griddle over medium heat for about 2-3 minutes.
05 -
Carefully place both sandwiches into the heated pan. Cook for 3-4 minutes until golden brown and crispy. Check frequently to avoid burning.
06 -
Gently flip the sandwiches and grill the other side, adding a little more butter if necessary, for 3-4 minutes until the cheese is fully melted and both sides are crispy and golden.
07 -
Remove the sandwiches from the pan and let them sit for a minute. Slice each diagonally and serve warm, garnished with fresh arugula if desired.