Add the ground beef, ground pork, egg, onions, sandwich bread, and seasonings together in a large bowl.
Roll the meatballs or use a cookie scoop (about three tablespoons) of meat mixture. As you roll them, place them into the air fryer basket. Set the temperature to 350 degrees F, air fryer setting, and cook for 15 to 17 minutes.
While the meatballs are cooking, make the sauce for the Swedish meatballs. Add the butter, all-purpose flour, beef broth, and heavy cream to a small saucepan.
Simmer, continue to whisk, bring to a slight boil, and cook for another 8 to 10 minutes until the sauce thickens.
To serve, place meatballs down on a plate, and drizzle them with the sauce.