Which ingredient is used at the bottom of a Breakfast burger?

The bottom of a Breakfast burger is appropriately represented by a crown-seeded bun. This type of bun serves as the foundational component of the burger, providing structure and support for the other ingredients that are layered on top. The seeds on the bun add texture and flavor, enhancing the overall taste experience.

While the beef patty, folded egg, and bacon are all key components of a Breakfast burger, they are placed above the bun rather than serving as its base. The crown-seeded bun's role is crucial in holding the burger together and creating a satisfying bite, making it the correct answer.