What ingredient is included in the Feenie burger?

The Feenie Burger features soy as an ingredient, which is particularly noteworthy because it refers to a specific flavor profile and texture that complements the other components of the burger. Soy often serves as a protein source and can enhance the umami flavor, which is key to this dish. While other choices are common ingredients in various burgers—such as pickles adding acidity, pineapple introducing sweetness, and mushrooms contributing earthiness and depth—soy stands out because it is a fundamental component of this particular burger recipe, aligning with the flavors and culinary vision represented at Cactus Club.