Preheat the oven to 400°F and line a large sheet pan with parchment paper.
In a mixing bowl, combine the ground turkey, panko breadcrumbs, egg, 1 tablespoon honey, 1 tablespoon Dijon mustard, 1/2 teaspoon salt, and 1/8 teaspoon black pepper. Mix gently until just combined.
Divide the mixture into four equal portions and shape each into a small loaf. Place the loaves on one side of the prepared sheet pan.
In the same bowl, toss the Brussels sprouts with the olive oil, remaining 1/4 teaspoon salt, and remaining 1/8 teaspoon black pepper. Spread them on the other side of the sheet pan.
Stir together the remaining 2 tablespoons honey and 2 tablespoons Dijon mustard. Brush the glaze over the tops of the meatloaves.
Bake for 22 to 25 minutes, until the meatloaves reach an internal temperature of 165°F and the Brussels sprouts are tender.
Sprinkle the chopped parsley over the finished dish before serving.