Take 1 pound of ground Wagyu beef and gently break it up into medium crumbles on a small sheet pan. Ensure it's spread out in a single layer. Sprinkle 1/2 teaspoon of salt and 1/2 teaspoon of onion powder evenly over the crumbled beef. Use your hands to gently toss the beef, distributing the seasoning throughout.

With minimal handling, form the seasoned beef mixture into four equal-sized patties. Apply as little pressure as possible while still ensuring the patties hold together well.

Preheat a cast iron skillet over medium heat. Add 1 teaspoon of vegetable oil to the skillet and allow it to heat up.

Carefully place the formed beef patties into the preheated skillet. Cook for approximately 6 minutes on one side without disturbing them. This allows for a nice sear to develop.

After 6 minutes, gently flip the patties using a spatula. Place 1 slice of cheddar cheese on top of each patty. Continue cooking for another 6 minutes for medium burgers, allowing the cheese to melt and the patties to cook through.

While the patties are cooking, split the brioche burger buns and spread any desired condiments, such as mayo, ketchup, mustard, or relish, on the bottom halves of the buns. Add a piece of leaf lettuce and a few slices of tomato to each bottom bun. Optionally, add pickles and a drizzle of BBQ sauce for extra flavor.

Once the patties are cooked to your desired doneness, place each patty on top of the tomato slices on the prepared bottom buns. Top each patty with the top halves of the buns.

Your delicious Wagyu beef burgers are now ready to be served! Enjoy these juicy and flavorful burgers with your favorite sides, such as fries or a salad.