Begin by caramelizing the onions. In a skillet, put a drizzle of oil and add the onions. Season with salt and pepper to taste. Add in about ½ cup to 1 cup of water. Cook over medium high heat until water cooks out, then reduce heat to medium and continue to cook onions until they soften completely.
While the onions cook, line a sheet pan with parchment paper. Preheat the oven to 400 degrees. In a mixing bowl, combine the ground beef, French onion soup mix, eggs, Worcestershire, and salt & pepper. Form into a loaf on the sheet pan that is wide and about 1 ½ inches thick. Using a sheet pan here will help it cook faster than using a loaf pan. Bake for 20 minutes.
Remove meatloaf and top with caramelized onions and then shredded cheese. Return to oven for another 5 minutes, until cheese is melty. Remove from oven, slice, and serve with mashed potatoes and salad, or sides of your choice.