In a large mixing bowl, add the ground meat, almond flour, egg, heavy cream, minced garlic, and all of the seasonings. Gently mix everything together using your hands or a spoon just until combined. Avoid overmixing, as this can make the meatballs dense. Once mixed, shape the mixture into evenly sized meatballs, about 1 to 1½ inches in diameter, and place them on a plate.

Heat a large skillet over medium heat and add a small amount of oil or butter to prevent sticking. Once hot, add the meatballs in a single layer, making sure not to overcrowd the pan. Brown the meatballs on all sides, turning them carefully, until they develop a golden crust. They do not need to be fully cooked at this stage, as they will finish cooking in the oven. Remove the browned meatballs from the skillet and set them aside.

In the same skillet, reduce the heat slightly and add the butter. Once melted, add the garlic and cook for about 20–30 seconds until fragrant. Slowly pour in the beef broth while stirring, scraping up any browned bits from the bottom of the pan for extra flavor. Add the heavy cream, Dijon mustard, and remaining seasonings, then whisk until the sauce is smooth and well combined. Let the gravy simmer gently for a few minutes until it thickens slightly. Do not let it boil.

Lightly grease a baking dish and arrange the browned meatballs evenly across the bottom. Pour the creamy gravy over the meatballs, making sure they are well coated. If using any optional additions like cauliflower or mushrooms, tuck them in between the meatballs at this stage.

Place the baking dish in a preheated oven at 375°F (190°C) and bake uncovered for 25–30 minutes, or until the meatballs are fully cooked through and the sauce is bubbling gently around the edges.

Remove the casserole from the oven and let it rest for about 10 minutes before serving. This allows the sauce to thicken slightly and makes serving easier. Spoon onto plates and enjoy warm, creamy, comforting keto goodness.