Add the ground meat to a large bowl along with the breadcrumbs, garlic, egg, Worcestershire, paprika, thyme, oregano, salt, pepper, mayo, mustard, and the grated onion.
Mix very well with your hands until everything is evenly distributed throughout the mixture.
Divide the mixture into 4 balls that are exactly the same size. Use a burger press to form the burgers into a patty shape, or use your hands to pack the burgers into evenly shaped patties.
Grill over medium-high heat (or fry in a frying pan over medium-high heat) for about 5-6 minutes per side, or until the internal temperature of the burgers reach 165°F (74°C) measured with an instant read thermometer.
If you want to make chicken cheeseburgers, add a slice of cheese (we suggest emmentaler cheese) over each burger. If using a pan, add a couple tablespoons of water to the pan and put the lid on so that the steam melts the cheese.
Remove the burgers from the heat and let them sit for about 5 minutes before serving. This helps them stay juicy and prevents them from falling apart.
Serve on toasted buns with lettuce, tomato slices, red onions, and a generous amount of burger sauce.