In a large bowl, combine ground turkey, onion, egg, ketchup, Italian seasoning, pepper, salt, and bread crumbs. Mix until just combined (I use my hands). Do not overmix.
Divide meat mixture into 4 evenly sized mini meatloaves and place on a rimmed sheet pan, 13 x 18 inches.
Toss the potatoes and carrots with olive oil, salt, and pepper in a clean bowl. Arrange potatoes and carrots around meatloaves in an even, single layer.
Bake for 20 minutes, stir potatoes and vegetables carefully, and return to oven. Continue to cook for 10 to 15 minutes or until internal temperature of meatloaves registers as 165°F on an instant read thermometer and potatoes and carrots are tender. If desired, top meatloaves with additional ketchup in the last 2 to 3 minutes of cooking time.
Let cool for 5 minutes before serving.
Notes
Feel free to substitute vegetables you prefer or have in the fridge. Shorter-cooking vegetables can be added halfway through the total cooking time.
Any type of ground meat or a combination can be used. Choose meat with a lower fat percentage so the sheet pan meal doesn't get too greasy.
To make Whole30 compliant: Use almond meal/flour instead of breadcrumbs, or skip the breadcrumbs completely. Use a Whole30 compliant ketchup.
To make gluten-free: Use oats or oat flour instead of breadcrumbs.