Preheat the oven to 350°F. Peel the potatoes and boil them in salted water. Then drain them and allow the steam to escape. Add milk and butter, mash everything until smooth, and allow your mashed potatoes to cool.
For the meatloaf, chop up the onions, bell peppers, garlic, and parsley and combine with the ground beef, eggs, bread crumbs, salt, and pepper.
Create a weave out of 10 slices and place it on a piece of parchment paper. Then make another weave with the other 10 slices of bacon. Allow the bacon weaves to sit for about 30 minutes.
Turn both oval glass casserole dishes upside down so the open side faces downward and grease them. Cut the mozzarella ball in half down the middle and place one half in the middle of the glass bowl. Now press the mashed potatoes around the mozzarella.
Press half of the meatloaf mixture around the mashed potatoes and form everything into the shape of an egg half.
Place the bacon weave on the meatloaf mixture and firmly press it down. Repeat the same process with the second half of the egg. Refrigerate both halves for about 30 minutes.
Remove both meatloaf halves from the glass dishes and press them together to create one big egg. (This works best if you put the egg in the freezer for at least 12 hours and then put it in the oven the next day). Place the egg upright in an ovenproof dish and cook at 350°F for 90 minutes.