Shake Shack's 'Shroom Burger forgoes the constraints of the patty form to present a mushroom in its most dignified state—breaded, fried, and full of cheese. GET THE RECIPE ►► https://f52.co/2KXpc9I Makes: 4 Prep time: 30 min Cook time: 1 hrs Ingredients: For the mushroom caps and filling: 4 4-inch portobello mushroom caps 1/4 cup canola oil, plus more for deep-frying 1/2 teaspoon kosher salt 1/8 teaspoon freshly ground black pepper 1 1/2 cups plus 1/4 teaspoon flour, divided 3 eggs plus 1 egg yolk, divided 2 cups panko breadcrumbs 1 1/2 cups grated Muenster 1/2 cup grated cheddar 1/2 teaspoon minced onion 1/8 teaspoon minced garlic 1 dash Kosher salt 4 tablespoons ShackSauce (below) 4 hamburger potato buns, toasted 4 pieces green leaf lettuce 8 1/4-inch slices ripe plum tomatoes For the ShackSauce: 1/2 cup Hellman's mayonnaise 1 tablespoon Dijon mustard 3/4 teaspoon Heinz ketchup 1/4 teaspoon kosher dill pickling brine 1 pinch cayenne pepper SUBSCRIBE TO FOOD52 ►► https://f52.co/2HN7Dp8 CONNECT WITH FOOD52 Web: https://food52.com Facebook: https://www.facebook.com/food52 Instagram: https://www.instagram.com/Food52 Pinterest: https://www.pinterest.com/food52 Twitter: https://twitter.com/Food52 Food52 newsletter: https://f52.co/newsletter ABOUT FOOD52 As a one-stop shop for joyful living, Food52 connects discerning home cooks with the interests they're passionate about via award-winning food and lifestyle content across platforms. We provide our audience with the recipes and solutions they crave to eat thoughtfully, live joyfully, entertain beautifully, and travel differently.