01 - Preheat oven to 375°F. Lightly grease a standard 6-cup muffin tin or line with muffin liners.
02 - In a large mixing bowl, combine ground turkey, onion, carrot, celery, and garlic. Add breadcrumbs, egg, milk, parsley, thyme, salt, pepper, and Worcestershire sauce. Mix gently until just combined — do not overwork the meat.
03 - Divide the mixture evenly among the muffin cups, pressing lightly to fill each cup.
04 - In a small bowl, mix together ketchup, brown sugar, and Dijon mustard. Brush the glaze generously over the tops of each meatloaf muffin.
05 - Bake for 25 minutes, or until the muffins are cooked through and the tops are caramelized. Internal temperature should reach at least 165°F.
06 - Allow to rest 5 minutes before removing from the tin. Serve warm.