Warm a skillet with a touch of olive oil, then gently sauté the minced onion with a pinch of salt until it's soft and clear. Take it off the heat and let it cool down a bit.
In a spacious bowl, combine the eggs, parsley (saving a teaspoon for a fresh garnish later), salt, pepper, garlic salt, almond flour, nutmeg, allspice, Worcestershire sauce, and the cooled sautéed onion. Mix these ingredients thoroughly. Next, add the ground beef and pork, blending everything until well combined.
Shape the meat mixture into uniform meatballs (a cookie scoop helps keep them even). Sauté these in olive oil (or your preferred keto-friendly oil) until beautifully browned on all sides. As they finish cooking, transfer them to a plate lined with paper towels to drain any excess oil.
Pour out most of the cooking fat from the skillet, then return it to the heat. Pour in the chicken stock to deglaze the pan, scraping up any flavorful bits. Stir in the sour cream and heavy cream until smooth.
Gently return the browned meatballs to the skillet with the sauce. Let them simmer together for 15-20 minutes, or until the creamy sauce has thickened to your desired consistency. Serve warm and savor!