In a sauté pan, heat the oil and add the onions and garlic. Sauté without color until softened. Add the carrot and the chopped mushrooms and continue to cook until carrots are tender and liquid from mushrooms are evaporated. Remove from heat and allow to cool. Set aside until ready for use.
Pre-heat oven to 350°F. In a large bowl, combine the Worcestershire sauce, first amount of ketchup, breadcrumbs, parsley, salt, pepper, ground turkey with the previously cooled ingredients along with the whole egg. Mix thoroughly, shape into a loaf shape on a parchment lined baking sheet. Place in the oven and cook the meatloaf for 40 minutes or until an internal temperature of 165°F degrees is reached.
Half way through cooking, mix together Thai sweet chili sauce and second batch of ketchup and brush onto of meatloaf. Return to oven and finish cooking. Remove from oven, allowing to rest for 10 minutes before slicing.