1. In a medium saucepan over medium heat, combine the shredded chicken and BBQ sauce. Stir until the chicken is thoroughly coated and heated through, about 5 minutes. Set aside.
2. Spread butter evenly on one side of each slice of sourdough bread.
3. Heat a large skillet over medium heat. Place one slice of bread, buttered side down, onto the skillet.
4. Layer with 1/4 cup of shredded cheese, followed by a generous portion of the BBQ chicken mixture, a few slices of red onion, and a sprinkle of cilantro if desired.
5. Top with another 1/4 cup of cheese and another slice of bread, buttered side up.
6. Cook until the bread is golden brown and the cheese has melted, about 3-4 minutes per side. Use a spatula to press down gently, ensuring the sandwich is crispy and the cheese is gooey.
7. Repeat with the remaining ingredients to make additional sandwiches. Serve hot and enjoy the nostalgic comfort in every bite.

Just like those cherished moments in my grandmother’s kitchen, making these sandwiches is about trusting your senses. Cook until the aroma tells you it’s time to flip, and tweak the ingredients based on what you have or prefer.