My Full Meal Meatloaf

Name: My Full Meal Meatloaf
Ingredients: 1 lb ground beef; 1 onion (peeled); 4 red potatoes (unpeeled); 1⁄4 large cucumber (unpeeled); 2 medium carrots (unpeeled); 1 medium tomatoes; 1⁄4 cup fat free sour cream; 1⁄4 cup Worcestershire sauce; 2 tablespoons garlic powder (separated); 1 teaspoon ground pepper (to taste); 1 teaspoon salt (to taste); 1 teaspoon thyme (to taste); 1 teaspoon oregano (to taste); 1 tablespoon taco sauce (optional topper)