Grate the onion and garlic into a medium size bowl; then add the Panko breadcrumbs and stir to combine. Set aside.
In a large bowl, add the ground beef and ground sausage. Break up the meat with a fork. Add the remaining ingredients and the reserved breadcrumb mixture. Use your hands to blend the mixture together. Do not over mix or the meatballs will be tough.
Scoop the meat mixture into 2-inch size meatballs, rolling them in the palm of your hand to create a smooth meatball. Transfer the rolled meatballs to a plate as you roll each one. Alternatively, scoop the meat and place on a sheet of parchment, then roll each one.
Once all the meatballs are rolled, heat 2 tablespoons of oil in a large skillet over medium-high heat. Working in two batches to avoid overcrowding, add the meatballs and cook until browned on all sides. Use tongs to gently turn them as they brown. Transfer each batch to a paper towel-lined plate.At this point, the meatballs are ready to serve, simmer in sauce, or cool for storage.
Notes
Tender Meatball Tip: For juicy, tender meatballs, don’t overwork the mixture. Mix with a light touch, just until everything is combined.Shaping Tip: Keep a small dish of water nearby to dip your fingers in as you roll the meatballs. It helps prevent sticking and makes shaping easier.Uniform Size: Use a medium cookie scoop for evenly sized meatballs—about 2 inches each.If Simmering in Sauce: No need to fully cook the meatballs beforehand if you’re adding them to hot marinara sauce. They’ll finish cooking as they simmer.Baking Instructions (Alternative to Frying): Place a cooling rack over a foil-lined baking sheet and arrange the meatballs on top. Bake at 400°F for 15–20 minutes, or until cooked through (internal temperature should reach 160°F).Make Ahead & Freezing Tips: These meatballs freeze well! Cook them completely, let them cool, then freeze in a single layer on a baking sheet. Once frozen, transfer to a freezer-safe container or zip-top bag. To reheat: bake from frozen at 350°F for 15–20 minutes or simmer in sauce on the stovetop until heated through.Serving Suggestion, Meatballs and Spaghetti: In a large skillet, heat your favorite jar of marinara sauce (or use homemade). Add the cooked meatballs and simmer on low heat while you cook 16 ounces of spaghetti. To serve, divide the spaghetti among bowls, top with sauce and meatballs, and garnish with chopped parsley and Parmesan cheese.