Combine yellow onion, garlic, seasoned bread crumbs, eggs, Parmesan cheese, milk and fine seas salt in a large mixing bowl.
Add ground meatloaf mix (veal, pork and beef) to large mixing bowl, breaking apart into smaller pieces as you go. Gently toss with your hands until evenly combined, some bits of bread crumb mixture might still be visible, that is okay.
Line a 9x5 loaf pan with parchment paper. To create my own "meatloaf pan", I put a few holes in the bottom to allow fats to drip out. You can also use an actual meatloaf pan.
Take half of the mixture and press it into the loaf pan. Place shredded carrots and zucchini in a mound down the center and then cover all around and top with remaining meat mixture. Press it all down snuggly to pack it in.
Bake for 1 hour and 20 minutes at 350 degrees. Remove and allow to cool for several minutes before removing from the loaf pan. Allow fats to drain on a seperate plate before transferring to a serving dish and cutting. (This step won't be necessary if you are using a meatloaf pan.)
If you've tried this recipe, come back and let us know how it was!
I put my onion and garlic in a small food processor and then made it into a paste.