What is the main protein used in Orange Chicken from Panda Express?

The main protein used in Orange Chicken from Panda Express is chicken. This dish features bite-sized pieces of chicken that are battered, fried, and then coated in a sweet and tangy orange sauce. The use of chicken not only aligns with traditional Chinese cuisine, where chicken is a staple protein, but it also contributes to the dish's appeal due to its tender texture and ability to absorb flavors.

In contrast, the other options like beef, pork, and tofu do not represent the primary ingredient in this specific dish. While these proteins may be used in various other menu items or dishes, they are not associated with Orange Chicken, which is specifically recognized for its chicken base.