Place baguette or white bread in a small bowl. Pour milk or water over it until submerged (you may need to push down as it tends to float to the top). Leave to soak while you're preparng the meat mixture.
Melt 1 tablespoon butter or add oil in a small or medium skillet. Add chopped onions, cook for a few minutes until softened, then add mushrooms and cook together on low medium heat for about 5 minutes, stirring often. Set aside and let cool slightly.
Add minced garlic, stir and cook for another minute, until fragrant.
Check if the bread is softened (it shouldn't feel hard inside or on the edges). Using clean hands squeeze out most of the milk or water from the bread. Discard the liquid.
In a large bowl combine ground turkey (or pork), squeezed out bread, cooked onions and mushrooms, egg, salt, pepper and marjoram.
Mix well using your hands or a spoon. It should be uniform and you should not be able to see big bread pieces in the mixture. Break them down with your fingers, if needed.
Form 7-8 round or oval patties (about 1-inch thick) and coat each in breadcrumbs on both sides.
Heat 3 tablespoon of oil in a large skillet.
Sauteé the patties on medium heat on one side until browned, then flip and cook on the other side. Each patty should register at least 160 degrees Fahrenheit on a kitchen thermometer (inserted in the middle). You can also take one kotlet off the pan, cut it in half and make sure it's no longer pink in the middle.
Serve immediately.