Scoop 1/4 cup of the kofte mixture into the palm of your hand (your left hand if you are right-handed). Wet your hands occasionally throughout the process to keep the meat from sticking. Shape the mixture into a ball, then use a finger (an index finger or thumb) to press into the center of the ball (use the fingers on your right hand if you are right-handed). While cupping the kofte with your other hand, carefully spin the kofte and keep pressing with your finger to expand the indentation. Keep doing this, carefully working the meat to yield an even thickness all around. Get it as thin as you can without tearing or losing structure. It should look like a wide meat cup.
Pack the inside of the kofte cup with about 2 heaping tablespoons of gheyma (the capacity will depend on how thin you got the walls of the kofte). Again, keep wetting your hands as needed. Carefully turn the kofte in your hand, using your other hand to seal the ball closed as you turn. You want to keep the exterior as even and thin as possible. Smooth out the ball either into an oval or round shape and set it on a sheet while you continue to shape the other koftes. While you work, occasionally wet the beef/bulgur mixture in the mixing bowl, and mix it again to ensure it doesn't get dry. If desired, for one of the koftes include an almond or hazelnut in the middle of the filling before sealing up the kofte. Whoever gets the kofte with the nut inside is the lucky one! (Only do this if you are sure all diners are not allergic to nuts!). Cover and refrigerate for up to 2 hours if you're not cooking them immediately.
Add 3 quarts of water, 3 tablespoons of kosher salt, and 3 tablespoons of lemon juice to a large pot and bring to a boil. In batches, add koftes. Boil for about 10 minutes, reducing the heat to medium to maintain a gentle boil/simmer. Use a slotted spoon to remove koftes to a strainer, and let rest for minute to finish draining. Transfer to a serving dish and serve immediately with lemon wedges.