A burger is only as good as the meat it's made from.
With a stuffed burger, the only choice is 100% beef, you won't find meat as good as that.
For the tastiest burgers, always pick meat with an 80:20 lean to fat ratio, as anything lower on the fat side would dry out quickly and produce a tasteless piece of leather.
Additionally, consider grinding the meat yourself for maximum freshness and taste, though pre-ground beef will work fine.
While different beef recipes call for different additives to burger meat, simple is usually better.
With that in mind, do not mix in any additional ingredients to your ground meat.
All they'll need is a coating of salt and black pepper after they're formed to help bring out even more of the natural beefy goodness.
If you have a preferred beef burger recipe, though, feel free to use it, as there's no such thing as too much flavor.
For a cheese-stuffed burger, you can use pre-shredded cheese if you like, but grating it yourself usually ends up with a better product.
This is because the shredded cheese in bags is coated with an anti-clumping chemical that makes it melt less easily, and melting is the name of the game when it comes to stuffed burgers.
Additionally, if you want to use different cheeses than the ones listed above, try to pair a strong tasting cheese like cheddar with a good melting cheese like mozzarella.
When stuffing a burger, you'll actually need two patties for each which you'll layer on top of each other with your fillings in the center.
Both of these patties should be rounded and slightly larger in diameter than the buns you intend to put them on, flattened out to about 1/4 of an inch thick with a lip around the edge (think of it like crust on a pizza).
Form your patties in pairs on a large work surface, filling one of a set of two with a couple tablespoons of shredded cheese.
To prevent meat from sticking to your hands, try wetting them in a bit of water before you go to form each patty.
When half your patties are filled, take the other half and carefully place them on top of the filled ones, matching the edges as best you can. It can help to use a spatula to quickly scoop up a patty and flip it over when doing this.
When the patties have been positioned right, use your fingers to gently squeeze the seems together until the patties have completely formed into one.
Do this for every set of patties until all your burgers are sealed shut, being careful not to leave any gaps whatsoever to avoid a blow out.
Place the finished patties onto a plate or sheet pan and chill in the fridge for 15 minutes to let them firm up slightly.
While your patties firm up, take the opportunity to light the grill.
Burgers cook best over a high flame, but you should also remember to leave a space for low or indirect heat where you can toast your buns, onions, or other foods that might easily burn.
By the time your burgers have finished chilling, your grill should be plenty hot
This is especially true for stuffed burgers, where structure is the only thing standing between a delicious meal and a terrible mess.
Season both sides of your beef burgers with salt and black pepper, then press a divot into the centers and get ready to grill.
Place the burgers over direct heat and do not move them.
Stuffed burgers are likely to be more fragile than normal burgers, so excessively flipping or moving them around increases the likelihood that they're fall apart at some point.
It also interferes with their ability to develop a thick crust and good grill marks.
When the edges of the patties begin to brown, flip them only once and leave them be.
You can also toast your buns at this stage, buttering or oiling both sides and placing them on low heat to medium heat for 30 seconds on both the tops and bottoms.
After a few more minutes, you can begin checking your burger for doneness.
Insert the thermometer into the side while trying to avoid the filling.
Burgers are suggested to be cooked to an internal temperature of 165 degrees Fahrenheit, which is likely a good idea when it comes to stuffed burgers that contain filling exposed to raw meat.
Ideally, take your burgers off at around 160 degrees Fahrenheit, as they will continue to cook for a short time after being removed from the heat.
When they've cooked fully, place them onto a clean plate or platter and tent them loosely with aluminum foil for a few minutes.
Resting is extra important when it comes to burgers as it helps them to retain much of the juice they'd otherwise loose due to being more well done than most beef products.
Additionally, in the case of a burger stuffed with cheese, it allows the filling to cool down a bit so you don't burn the inside of your mouth on your first bite.
After your burgers have had a chance to finish cooking and rest, it's time to eat.