Put a large pot of water on to boil and cover it with a lid so the water comes to a boil fast. Have a GH (Grown-Up Helper) give you a hand if the pots too heavy for ya. When the water boils, add salt and the pasta shells and cook until the shells are almost done, 7 to 8 minutes; they should still have a little bite to them. Drain the pasta or have your GH do it for you. Remove the foil wrapping from the cream cheese, place the cheese in a microwavable bowl and soften in the microwave, on high, for 30 seconds.
Grate the onion over a plate. Heat a medium saucepan over medium heat. Add the EVOO, 1 turn of the pan, and the butter. When the butter melts into the EVOO, scrape the onion and its juice into the butter and add the garlic, then cook for 3 minutes. Using a fork, remove the big hunks of garlic. (The flavor of the garlic goes all through the butter and oil as soon as it heats up.)
Sprinkle the flour into the pan and cook over medium heat for 1 minute, stirring continuously. Whisk in the broth and then the milk. Let the liquid come up to a bubble, then mix in the cream cheese until it melts and blends into the milk and broth completely. Stir in the veggies and simmer over low heat for 5 minutes. Stir the grated Parmigiano-Reggiano cheese into the sauce and remove the pan from the heat. Season to taste with salt and pepper.
Return the hot pasta to the pot it was cooked in and add the sauce with the veggies. Stir together and add more cheese, salt and pepper, if desired. Place the pasta in bowls and top with the chives. Yum-O!