Put one slice of stale or toasted (on both sides) bread into a food processor and pulse to make the bread crumbs. Mix the bread crumbs into the mushroom mixture in the bowl, then add the meat, and mix again, making sure not to overwork the meat. Add the beaten egg, sprinkle half of the spice-blend into the bowl, and mix again.

Move the meat to a flat baking sheet or casserole and shape into loaf, approximately 8" x 5" x 2" height for a 4-serving meal, slightly larger or smaller for more or less servings. Put the dish into the oven and bake for about 50 to 60 minutes, until full cooked and browned on the outside. Return the skillet with the remaining mushroom mixture to the stove, and heat over a medium flame. When the mixture is hot and glistening, stir in the the remainder of the paprika spice and the stock blend. Cook, stirring occasionally, until it begins to simmer.

Put the sour cream into a medium bowl, and add to it 1/4 cup of the hot liquid from the mushroom mixture in the skillet. Stir until combined and warmed. Stir the tempered sour cream and the heavy cream into the mushroom mixture, then heat until warmed, about 5 minutes. Taste, and add salt if needed.

Carefully put about 3 or 5 meatballs into a shallow bowl, spoon in the sauce, and then carefully extract an egg with a serving spoon and place the egg into the serving bowl and garnish with parsley or cilantro. It can be served as-is, or over a small dab of a low-carb cauliflower mash.