Preheat oven to 400°F.
Sauté the onions and carrot in oil in a 12" skillet over moderate heat for 2-3 minute until the onions have just softened.
Add red pepper, corn and continue to sauté, stirring frequently until they have softened, 3 minutes.
Add the garlic and cook for another minute until fragrant.
Add mushroom, salt and pepper, thyme and cook, stirring occasionally, until the liquid the mushrooms give off has evaporated and they are very tender, 10-15 minutes.
Stir in the Worcestershire sauce, 1 tablespoon ketchup and the parley. Cook stirring for another 30 seconds and transfer to a large bowl and allow to cool.
I like to pulse the ground turkey in the food processor a couple of times to give the loaf a finer texture.
Add the turkey, breadcrumbs, egg and egg white and mix well. I like to do this with my hands to evenly distribute the vegetables through the meat.
Put 1 tablespoon of ketchup into the loaf pan and using a rubber spatula spread it evenly onto the bottom and all for sides.
Using the same spatula, transfer the turkey mixture into the pan, pressing it into the corners and smoothing the top.
Evenly spread the remaining 2 tablespoon of ketchup on the top and put in the middle of the oven to bake for 50 - 55 minutes, until an inserted thermometer registers the center temperature to be 170°.
Let meatloaf stand for five minutes before serving.