In a medium bowl, mix 2 cups of shredded rotisserie chicken with ½ cup of your favorite BBQ sauce until evenly coated. Let the flavors meld together while you preheat a skillet over medium heat for about 5 minutes.

Take two slices of sourdough bread and generously butter one side of each slice. On the unbuttered side, layer a mix of ¼ cup of shredded cheddar and ¼ cup of Monterey Jack cheese. Spoon ½ cup of the prepared BBQ chicken mixture on top of the cheese, then top with another layer of cheese before placing the second slice of bread on top, buttered side facing out.

Carefully place the sandwich in the preheated skillet and cook for about 3-4 minutes, pressing down gently with a spatula. After 3 minutes, check the underside; it should be golden brown and crisp.

Using a spatula, carefully flip the sandwich over to grill the other side, allowing it to cook for another 3-4 minutes until golden brown and cheese is bubbling out.

Once both sides are beautifully brown and the cheese is melted, transfer the sandwich to a cutting board. Allow it to rest for a minute, then slice it in half for easy handling.