Place a medium-sized pot over medium heat. Add butter and cook until just melted. Add the jalapeno and garlic to the butter. Cook for 1 minute stirring constantly until fragrant. Add flour and whisk to combine. Cook for 1 minute.
Slowly pour the half-and-half into the pot whisking constantly to help prevent lumps. Cook for 8 to 10 minutes or until the sauce has thickened, whisking occasionally. Remove from the heat and set aside.
Place the bacon strips in a large skillet and cook over medium-high heat, turning as needed, until crispy, about 8 minutes. Remove to a paper towel lined plate to drain. Once cool enough to handle chop the bacon into small pieces.
While the bacon & sauce cooks, place the jumbo shells in a pot of boiling water and cook according to package directions until al dente. Drain the pasta and set aside.
To a large mixing bowl, add the Neufchatel cream cheese and 1 1/2 cups of the cheddar cheese. Use a wooden spoon or sturdy rubber spatula to stir until combined.
Add the shredded chicken and 2/3 of the bacon to the cheeses. Stir to combine.
Add 1/3 of the jalapeno cream sauce (it's fine that the sauce is still warm) and stir until combined. The sauce will help loosen the cream cheese mixture.
Pour 1/3 of the jalapeno cream sauce into a 9-inch x 13-inch baking dish. Spread into an even layer.
Use a spoon to stuff the jumbo pasta shells with the chicken jalapeno popper filling. Don't be afraid to add a generous amount of filling. Arrange the stuffed shells in the prepared baking dish until filled.
Spoon the remaining sauce over the shells. Sprinkle the rest of the cheddar cheese over the shells.
Bake for 20 minutes, or until the cheddar cheese is melted and the filling is warmed through.
Carefully remove the baking dish from the oven. Immediately top the pasta with the jalapeno rings and reserved bacon. Serve immediately.
Rotisserie chickens can be found near the deli section of the grocery store.