Place the bread in a bowl. Add enough water to cover the bread and a bit more. Let the bread soak for a while. When you are ready to use it, press the bread into a strainer to release as much water as possible.

Mix together ground beef, eggs, onion, pepper, salt and ketchup. Stir in bread gradually until you have the right consistency. Set aside.

Heat oil in a skillet on medium-high. Fry garlic until golden brown. Add onion and sauté for only two minutes. Throw in peppers and mushrooms and sauté for three to four minutes or until they are just starting to soften. The vegetables should retain some of their shape and crispiness. Season with salt and pepper. Remove from heat and add parsley.

Make thin patties of ground beef by taking a ball of the meat mixture between your hands and pressing down on it to create a flat disc.

Pat a spoonful or more of the vegetable mixture on top of the disc. Then cover with another thin patty and seal in the vegetables by pinching the sides lightly together.

Preheat grill or broiler. Grill or broil burgers on each side for five minutes, or longer if you prefer your burgers well done.