In a large bowl, add ground beef, crush pork rinds, 1 teaspoon of salt, spices, egg, and 2 tablespoons of heavy cream Gently fold ingredients together.
Roll about 1 ½ tablespoons of ground beef mixture into a ball, repeat with remaining ground beef mixture. This should make about 24 meatballs.
Melt butter in a large pan over medium to medium high heat. Add in onions and a teaspoon of salt. Cook onions, stirring occasionally, until they are soft and golden -about 5-7 minutes.
Remove onions from the pan, and leave in any remaining butter.
Warm olive oil into the same pan and add in meatballs. Brown meatballs on all sides over medium high heat, and then lower heat to medium/medium low and cover pan. Every 3-4 minutes, rotate meatballs until they are cooked through. Total time can take between 10-20 minutes, depending on how thick you made your meatballs.
Remove meatballs from pan, once cooked through.
Return heat to medium high, add in broth, mustard, and remaining heavy cream. Mix well, and allow sauce to come to a simmer. Keep it at a gentle simmer for about 2-3 minutes.
While sauce is simmering, in a small bowl, whisk together water and xantham gum or arrowroot. Mix until smooth to create a slurry.
Gently pour in your slurry to the pan and whisk ingredients together to keep from forming lumps.
Lower heat to medium or medium low and continue to cook sauce for an additional 4-7 minutes or until sauce thickens.
Add in your onions and meatballs and cover meatballs with the sauce and continue to gently simmer until meatballs have warmed through again.
Garnish with parsley and serve.