In a bowl, combine the beef mince, egg, and salt and pepper seasoning. With your hands, combine until everything is fully incorporated. Roll the mix into 4 even balls with your palms and set aside.

Fire up your Ooni pizza oven. Aim for 500˚C (952˚F) on the stone baking board inside. You can check the temperature inside your Ooni quickly and easily using the Ooni Infrared Thermometer.

Place your cast iron Skillet pan, sizzler pan, or dual sided grizzler pan (flat side up) inside your oven to preheat.

After 10 mins, your pan should be nice and hot. Remove the pan and place two of your meatballs onto the hot pan. Using either a meat press or the base of another cast iron pan, smash the burgers down firmly, and keep the weight while the bottom half cooks. After 4-5 minutes, remove the weight and check the bottom side – if brown and crispy, flip, and return the press to the cook on the other side. After a further 4-5 minutes, your burgers should be nicely browned and cooked through. Remove and set aside while you finish cooking the remaining two meatballs.

Once your burgers are cooked, heat the butter in the residual heat of the pan. Place your slide brioche buns face down in the hot butter and allow each side to toast golden brown. You might need to return the pan to the oven to heat a little more.

Now it’s time to stack your burgers! Start with your lettuce, then tomato slices, your first burger, gouda slice, second burger, pickle, red onion, and finally your top bun (with an even layer of burger sauce spread over the base!). Press down with your hands, and seal with a cocktail flag or skewer. Serve immediately with a cold beer and side of fries.