Shake Shack’s first-ever cookbook, “Shake Shack Recipes and Stories,” has caused quite a stir, especially since the chain’s fine-dining origins mean the food is a cut above typical fast food fare, and, therefore, features favored menu items that are a little easier to recreate at home. While making home versions of popular restaurant dishes isn’t new, it’s not often that the chain doles out the recipe. Fortunately, Shake Shack is quite generous and isn’t shy about revealing its most sought-after dishes, as seen when it fully showcased its secret menu peanut butter and bacon ShackBurger online. Now, thanks to the cookbook, we have the recipe for the iconic ‘Shroom burger, a vegetarian burger that holds its ground amidst all the chain’s other offerings. At the heart of the ‘Shroom burger lies a thick and juicy, crumb-fried portobello mushroom stuffed with molten cheese. The patty packs such a punch that the burger doesn’t have to rely on much else, save for a simple layering of tomato, lettuce, and ShackSauce.
Save for fresh portobello mushrooms, you probably have the rest of the ingredients for a ‘Shroom burger at home already. Since the mushroom is the burger’s highlight, it must be prepped carefully. Most tend to focus on the cheese filling, wondering how it gets into the mushroom. Turns out, portobellos mushrooms are the ideal mushrooms for stuffing. To help draw out their deep umami notes and meaty texture, it’s important to roast them first. This is the crucial step you shouldn’t skip when making Shake Shack’s ‘Shroom burger at home.
Why you should roast mushrooms for the ‘Shroom burger
Mushrooms have a high water content, meaning raw mushrooms have a mild flavor that gets increasingly concentrated as their moisture is cooked away. Portobello mushrooms are more mature than smaller cremini and button mushrooms and tend to have a lower water content, giving them a richer flavor. However, to enjoy them best, more water still needs to be extracted from those portobellos, which is where roasting comes in. Plus, it lets you get an extra layer of seasoning on the mushrooms, so make sure you give them a nice coating of oil, salt, and pepper before putting them in a 375-degree Fahrenheit oven for about 30 minutes.
The Shake Shack recipe calls for slicing the mushrooms in half after they are baked to give them that cheesy center. However, it’s easier to cut raw mushrooms, so split them (as you would a burger bun) before roasting. Since even large portobellos can vary in size, sometimes a single mushroom may be too small to transform into a cheese-filled patty. In that case, you can use two smaller portobello mushrooms instead of one. Simply scoop out the gills, place the cheese mixture inside, and top it with the other mushroom with the hollowed side down before breading and frying.
To save time, you can cover the mushrooms and microwave them on high for about 5 minutes. While this method is much faster, the results are slightly less delicious since the mushrooms don’t get as dehydrated and their flavors don’t concentrate as much. Rushing the cooking process is one of the many common mistakes people make with mushrooms, so when microwaving, make sure they’re cooked through and pat them dry before frying them into a burger patty.
