Preheat the oven: Start by preheating your oven to 350°F (175°C). Spray a 9x13-inch baking dish with cooking spray to prevent sticking.
Prepare the base: Pour 1/4 cup of salsa verde at the bottom of your prepared baking dish, spreading it evenly to form a flavorful base.
Mix the filling: In a mixing bowl, combine 3 cups of shredded rotisserie chicken with 3/4 cup of salsa verde until well blended. This flavorful mixture will be the filling for your enchiladas.
Assemble enchiladas: Taking a fajita-size tortilla, spoon 1/4 to 1/3 cup of the chicken mixture into the center. Sprinkle a little pepper jack cheese on top before rolling it up tightly. Place the tortilla seam-side down in the dish. Repeat this step for all tortillas until the mixture is used up.
Add the sauce: In the same bowl used for the filling, combine the remaining salsa verde (about 3/4 cup) with 2 tablespoons of half & half. Mix well and pour this creamy sauce over the assembled enchiladas. Top with the remaining pepper jack cheese.
Bake the enchiladas: Place the baking dish into the preheated oven and bake uncovered for 20-30 minutes, or until the cheese is bubbling and lightly golden on top.
Once baked, let the enchiladas cool for a few minutes, then serve warm. You'll know they're ready when the cheese is melted and the entire dish is enticingly fragrant.