Preheat oven to 425 degrees. Line a rimmed baking sheet with foil and spray with cooking spray.
Heat olive oil over medium heat in a small skillet until shimmering. Add onion and garlic and saute until soft, about 3-4 minutes.
Mix the cooked onion & garlic with the ground turkey, BBQ sauce, balsamic vinegar, bread crumbs, Parmesan, black pepper, sea salt, and egg in a large bowl, just until well combined.
Form the turkey mixture into four small free-form loaves, and arrange these on one end of the prepared baking sheet.
Combine all glaze ingredients and spoon glaze over the top of each mini meatloaf.
On the other end of the baking sheet, toss the green beans and potatoes with olive oil, seasoned salt, Italian seasoning, and minced garlic, then spread them out in a single layer.
Bake your mini turkey meatloaf sheet pan dinner at 425 degrees for 30 minutes, stirring vegetables halfway through (or until the mini meatloaves register 165 degrees internal temperature on a meat thermometer).
Remove pan from oven and let rest five minutes before serving.
Notes
Don't skip the foil, unless you really enjoy scrubbing pans...