3 tablespoons ketchup, plus more for brushing on top
1 tablespoon worcestershire sauce
½ teaspoon dried thyme
1 teaspoon salt
¼ teaspoon black pepper
3 garlic cloves, minced
Preheat oven to 350 F degrees. Spray a 4-1/2 x 8-1/2-inch loaf pan with cooking spray.
Heat the oil in a large nonstick skillet set over medium heat. Add the mushrooms, onion carrot, and celery. Cook, stirring frequently, until the onion is softened, about 5 minutes. Transfer this mixture to a large bowl.
Add the remaining ingredients to the vegetables in the bowl and mix well. Press the meatloaf into the prepared loaf pan.
Bake the meatloaf for 30 minutes. Brush additional ketchup on top of the loaf, if desired. Cook until done, an additional 30 to 45 minutes. (An instant read thermometer inserted into the center of the loaf should read 160 F degrees.)
Remove from the oven and let rest for about 5 minutes. Cut into 8 slices.