In a medium bowl combine the ground beef and seasonings. If your seasonings do not have salt and pepper included, add them in this step.
Divide the patties in about two inch balls for medium sized smash burgers.
Heat the grill over medium heat.
Have a plate of the hamburger patties, sliced cheese and sliced onions ready before you start grilling the smash burgers.
Use a large flat spatula to help flatten the burgers into thin smash burgers.
Move quickly on this next step when you start cooking the smash burgers.
On a preheated grill, add a slice of cheese. Immediately place the burger ball into the cheese slice and top it with the thinly sliced onions. Use a large spatula and press the burger down as thin as you can by smashing it down onto the cheese.
By placing the onions over the hamburger before you smash it, it creates a non stick barrier between the burger and the spatula making it really easy to smash the burgers. If you choose not to use onions then have another spatula or knife ready so you can slide the burger off of the spatula after you smash it.
Cook the burgers just long enough to see the cheese crust and the burgers brown on the edges. Smash burgers will cook quickly depending on how thin they are. It might only take about 2 minutes on each side.
Flip the burgers and finish cooking them on the other side. The first side you cooked with have a crispy cheese layer! SO YUMMY!
Remove from the grill and set on a tray with the crispy cheese layer faced up.
Slice the buns and heat them on the grill just before serving the burgers.
We add two smashed patties to each keto hamburger bun.
Add extra cheese to the hot burgers if you want melty cheese too.
Serve the burgers as is (very cheesy) or add toppings and enjoy!