Begin by blending the onion. I used a hand blender but you could also use a regular blender or food processor.

In a large bowl add all of the ingredients and mix them well together. I find that using my hands and squeezing it all together is the best way to mix it.

Split the mixture into 8 and form the beef burgers. I used an egg ring to get a good shape but you can easily just use your hands as well. Each burger uses about 1/2 a cup of raw meat mixture which is 4 oz. You could also use a kitchen scale to weigh each burger before shaping them.

The best way I've found to freeze hamburgers is by using freezer-safe storage containers with parchment paper, freezer paper, or wax paper. I find that raw meat sticks too much to aluminum so I'd avoid that.

Cut the paper into squares that are just a little bigger than the size of your patties.

Place two squares of parchment paper in the bottom of the container (or however many will fit without overcrowding).

Place a burger patty on top of each square, making sure the patties don't touch each other.

Top each burger patty with another piece of parchment paper, and repeat!

Seal the container with the lid and place it in the freezer.

After they're frozen, you can either keep them in this container or move the frozen burgers into freezer bags to save a little space.

Freeze the raw patties for up to 3 months.

After making the burger patties, you can either cook them in the oven, on the stove, grill them, or pop them in the air fryer.

Air Fryer: Preheat the air fryer to 175°C/350°F, and then cook the patties for 8 minutes, flip them, and cook them for another 4-6 minutes until cooked through.

Oven-baked: Preheat the oven to 220°C/425°F. Bake for 15 minutes (medium) or 20 minutes (well done).

Stovetop: Place a medium-large nonstick skillet over medium-high heat. When the pan is hot, cook the burger for about 5 minutes on each side.

Grilled: This will depend on how hot your grill is, but ideally, it would be between 230-260°C/450-500°F. Grill the burgers for 8-9 minutes, until cooked through.

Check the internal temperature with a meat thermometer. For fully cooked burgers, it should be at 71°C/160°F. Medium is 63°C/145°F, a medium-rare burger is 57°C/135°F, and rare is 52°C/125°F.

Next, allow the burgers to completely cool to room temperature. The easiest way to do this is by placing them in a single layer on parchment paper or a baking sheet on the counter.

When the homemade hamburgers have cooled, place patties in a freezer-safe container (I use a gallon size freezer bag or a pyrex container). It's a good idea to put a square of parchment paper or freezer paper between each pattie helps to keep them separated, and makes it easier to take them out to cook later. You can wrap patties in aluminum foil instead.

Freeze the burgers for up to 3 months.