You have to keep a couple things in mind when mixing the meat, veggies, spices, breadcrumbs and egg. Turkey is much softer and easier to mix with the breadcrumbs and vegetable mixture. So much so that you can over mix it rather quickly. Over mixing can create a spongy texture. Alternatively, the beef, particularly if it was cryovaced will be more difficult to work into an even texture with the veggies and seasoning. Either way, the best way to do the mixing is with clean dry hands, gloves are optional. {Make sure you have removed your rings! Yuck!} Then keep working it together until the breadcrumbs and veggies are evenly incorporated. Then stop. As I said, overworking will make the meatloaf spongy.