Heat a large high-sided skillet (with the lid set aside for later) over medium-high heat.

Once the pan is hot, add the avocado oil.

Add the ground beef and break it up into small pieces. Cook, stirring occasionally, until mostly cooked through, about 5 minutes.

(If there is more than a tablespoon of excess fat in the pan, drain it and return the meat back to the pan.)

Add the onions and 1 teaspoon of the salt and stir to combine. Cook until the onions start to become tender, about 5 minutes.

Add the garlic and cook, stirring constantly, until fragrant, 1 minute.

In the meantime, add the beef broth, half-and-half, the remaining ½ teaspoon of salt, pepper, cornstarch, dried parsley, and Worcestershire sauce to a large measuring cup and whisk to combine.

Once the onions and garlic are cooked, add the broth mixture and stir to combine.

Immediately add the egg noodles to the skillet and stir to combine, making sure that the noodles are mostly submerged.

Bring the mixture to a boil over high heat. Once boiling, reduce the heat to low and cover.

Cook, covered, until the noodles are tender and the sauce has thickened, 7 to 10 minutes.

Remove from the heat and stir in the sour cream and Parmigiano-Reggiano (it’s very important to do this off heat to prevent any separation).

Garnish with more cheese, fresh parsley, and a few cracks of black pepper.

Serve family style out of the skillet or divide among bowls.