Preheat oven to 350ºF (177ºC). Spray a 9x5-inch loaf pan with nonstick cooking spray. Line a rimmed baking sheet with parchment paper or aluminum foil; set aside.
In a large skillet, heat olive oil (2 tablespoons) over medium heat. Stir in onions (1 1/2 cups) and carrot then sauté until they begin to soften, about 4-5 minutes. Add garlic (1 tablespoon) and continue to sauté until fragrant, about 1 minute.
Stir in mushrooms (8 ounces) and Worcestershire sauce (2 tablespoons) then sauté, stirring often, until they release their liquids, about 8-10 minutes. Remove from heat and allow to cool for about 10 minutes.
Meanwhile, add the Panko breadcrumbs (1 1/2 cups) and milk (1 cup) to a large mixing bowl and allow the Panko to absorb the milk. When the onion mushroom mixture has cooled add to the Panko mixture.
Add mozzarella (1 cup), beaten eggs (2), Italian seasoning (1 tablespoon), sage (1/4 teaspoon), salt (1 1/2 teaspoons), black pepper (1/2 teaspoon), and ground turkey (2 pounds). Using your hands, gently mix until evenly combined.
Evenly press the meatloaf mixture into the prepared pan. Invert the pan onto the prepared lined baking sheet.
Make The Glaze:
In a small mixing bowl, whisk together all the glaze ingredients.
Pour 1/2 the glaze on top of the meatloaf. Use a pastry brush to evenly spread over the tops and sides. Do not put the pastry brush back in the glaze (for sanitary reasons).
Bake It:
Place meatloaf in preheated oven and bake for 30 minutes; remove from the oven and top meatloaf with remaining glaze.
Return the meatloaf to the oven and continue baking until an instant-read thermometer inserted into the thickest part of the meatloaf registers 160°F (71ºC), about 30 minutes more. Allow the meatloaf to rest for 10 minutes before slicing and serving.
Notes
So Tender! The trick to achieving a tender meatloaf is not to overmix the meat mixture. The panko bread crumbs panade soaks up all the flavor and moisture of the veggies, ensuring a moist meatloaf. This is our secret one-two punch!
Use Your Hands: Many people struggle with mixing the raw meatloaf with their hands. Trust me, they’re the best tools for the job. Of course, you need to make sure they’re well-cleaned. At step number five, when everything is in a large bowl, stick your hands in and mix!