BBQ Chicken Grilled Cheese

1 Tbsp olive oil
3 cups cooked shredded chicken
1/4 medium red onion, sliced
1/2 cup Copperhead Sauce
1/4 cup chopped fresh cilantro
3 Tbsp unsalted butter, softened
8 slices bread
8 slices thick cut pepper jack cheese

Heat oil in skillet over medium heat. Add in chicken and onion. Cook until chicken is warmed and onion is soft. Stir in Copperhead and cilantro. Set aside. Heat griddle to medium heat. Spread one side of each slice of bread with butter. Place one slice of cheese on non-buttered side. Spoon 1/2 cup of chicken mixture on top. Place another piece of cheese on top of chicken. Top with another slice of bread with the buttered side out. Cook sandwiches over medium heat 3-4 minutes each side or until golden brown and the cheese has melted.