Cook pasta until not quite done - al dente according to package instructions (it will finish cooking in the oven.) Drain, rinse, and set aside.

In a large pot, heat butter over medium-high heat. Add garlic and sauté for a couple of minutes. Add onion and salt, then sauté for a couple more minutes. Pour in the wine and allow it to cook with the onion for several minutes, or until the liquid reduces by half.

Sprinkle in flour, then stir the onion around for another minute. Pour in the broth and stir, cooking for another few minutes until the roux thickens.

Reduce heat to medium low. Cut cream cheese into pieces and add it to the pot. Stir it to melt (don't be concerned if the cream cheese remains in little bits for awhile; it'll melt eventually!) Cook pasta until not quite done - al dente according to package instructions (it will finish cooking in the oven.) Drain, rinse, and set aside.

Add the chicken, the bell pepper, the peas, the bacon, and the cheeses. Stir to combine, adding salt and pepper as needed.

Add the cooked spaghetti and stir it to combine. Splash in more broth as needed; you want the mixture to have a little extra moisture since it will cook off in the oven. If it's a little soupy, that's fine! Add up to 2 more cups of liquid if you think it needs it.

Pour the mixture into a large baking dish and sprinkle the top with Panko crumbs. Bake at 350 degrees F for 20 minutes, or until the casserole is bubbly and the crumbs are golden brown (you can use the broiler if you like it nice and toasty).