1-First Step: Prep and flavor base Heat 1 tablespoon of the olive oil in a large skillet over medium heat. Add 1/2 cup finely diced yellow onion and 2 cloves minced garlic. Sauté until softened and translucent, about 5 minutes. Remove from heat and let cool slightly. This softening draws out sweetness and reduces raw onion bite so the meatball mix remains balanced.

2-Second Step: Build the meatball mixture In a large bowl, combine 1/2 cup panko breadcrumbs, 1/4 cup Parmesan cheese, 1 large whisked egg, 1/3 cup milk, the cooled onions and garlic, 1 teaspoon salt, 1/4 teaspoon each dried oregano, ground allspice, ground nutmeg, and pepper. Stir until evenly mixed. Gently fold in 3/4 lb. ground beef and 1/2 lb. ground pork. Work the mixture just enough to combine it; overworking will make the meatballs dense. Form into 1 1/2-inch meatballs using your hands or a cookie scoop for uniform size. Place on a tray and chill in the refrigerator for at least 15 minutes or up to overnight. Chilling helps them hold shape while browning.

3-Third Step: Prepare the sauce base While the meatballs chill, whisk together 2 cups beef broth, 1 cube chicken bouillon, 2 teaspoons Worcestershire sauce, 1 teaspoon Dijon mustard, and 1 teaspoon dried parsley in a measuring cup. This will be added to the roux to become the creamy gravy.

4-Fourth Step: Brown the meatballs Heat the remaining 1 tablespoon olive oil in a heavy skillet over medium-high heat. Brown the meatballs in batches so you do not overcrowd the pan, about 1 minute per side, until they have color. They do not need to be cooked through; browning locks in flavor. Set browned meatballs aside on a plate.

5-Fifth Step: Make the roux and finish the gravy Drain excess oil from the skillet, leaving any fond for flavor. Melt 4 tablespoons butter in the same skillet over medium heat. Stir in 4 tablespoons flour and cook, stirring constantly, for about 2 minutes until it turns slightly browned and nutty. Gradually pour in the beef broth mixture while whisking to prevent lumps. Bring to a gentle boil, then reduce to a simmer. Taste and adjust seasoning if needed.

6-Sixth Step: Temper the sour cream and simmer Place 1/2 cup full-fat sour cream in a separate small bowl. Slowly whisk a few tablespoons of the warm sauce into the sour cream to temper it. This prevents curdling. Once smooth, return the tempered sour cream back into the skillet and stir over low heat until the sauce is creamy and homogeneous.

7-Final Step: Combine and finish cooking Return the browned meatballs and any collected juices to the skillet. Spoon sauce over the meatballs, cover partially, and simmer gently for 10 to 15 minutes or until meatballs are cooked through (internal temperature should reach 160 F for pork-beef mixes). Garnish with fresh parsley and serve over egg noodles, mashed potatoes, or rice.