📖 Instructions

1. First things first, let's get the glaze simmering. In a small bowl, whisk together the soy sauce, mirin, sake (if using), gochujang, honey, sesame oil, grated ginger, and minced garlic. Stir it all up until it's nicely combined. Set this aside for now.
2. Next up, the shiitake 'ghosts'. Gently remove the stems from the shiitake mushrooms. Heat a skillet over medium heat with a drizzle of sesame oil. Add the mushroom caps, gill-side up, and cook until they soften and become slightly golden, about 5-7 minutes. Flip them over and cook for another 3-5 minutes. Now, brush the shiitake caps generously with the prepared glaze and let them caramelize for the last minute or two. Set them aside, looking all ghostly and delicious.
3. Time to build those patties! In a large mixing bowl, combine the ground beef, panko breadcrumbs, chopped scallions, minced garlic, grated ginger, soy sauce, sesame oil, and a pinch of black pepper. Mix everything together gently with your hands until just combined. Be careful not to overmix, or your patties might become tough.
4. Divide the beef mixture into equal portions and shape them into patties, slightly larger than your brioche buns (they'll shrink a bit while cooking). Press a small indentation in the center of each patty with your thumb to prevent them from puffing up too much.
5. Now, heat a cast iron skillet or large pan over medium-high heat with a bit of oil. Cook the patties for about 4-5 minutes per side for medium doneness, or longer if you prefer them well-done. During the last minute of cooking, brush the patties with the glaze, ensuring they're nicely coated.
6. If you're adding cheese, now's the time! Place a slice of provolone on each patty and let it melt slightly.
7. While the patties are resting for a minute, lightly toast the brioche buns. This adds a delightful texture and prevents them from getting soggy.
8. Spread a dollop of kewpie mayo on both the top and bottom buns. This is crucial—it adds a creamy richness that ties everything together!
9. Now, assemble your masterpiece! Place a patty on the bottom bun, top with a couple of glazed shiitake 'ghosts', and sprinkle with sesame seeds. Crown it with the top bun and admire your creation. Take a moment. You earned it.
10. Serve immediately with your favorite sides, like sweet potato fries or a refreshing cucumber salad. Prepare for a flavor explosion that will haunt your dreams (in the best way possible!).