Sauté Your Aromatics (and Beef, if using): Drizzle about a tablespoon of olive oil into a large pot or Dutch oven over medium heat. Add the chopped onion and cook for about 3-4 minutes until softened. Toss in the minced garlic and cook for another minute until fragrant. If using ground beef, add it now and cook until fully browned. Drain any excess fat if necessary, then return the beef to the pot.

Add Pasta and Liquid: Pour in 4 cups of beef broth and add the 12-16 ounces of short pasta directly into the pot. Stir gently to ensure the pasta is submerged in the liquid.

Bring to a Boil, Then Simmer: Increase the heat to high and bring the mixture to a rolling boil. Once boiling, reduce the heat to medium-low, cover the pot, and let it simmer for about 12-15 minutes, stirring frequently to prevent sticking.

Stir in the Creaminess and Pesto: Once the pasta is cooked and most of the liquid is absorbed, remove the pot from the heat. Stir in the heavy cream, cream cheese (if using), and basil pesto until everything is combined and the sauce is smooth.

Season and Serve: Taste the pasta and season with salt and freshly ground black pepper as needed. Serve immediately, garnished with freshly grated Parmesan cheese.