This is how you sign Mustard in American Sign Language.

How to sign

To sign "Mustard" in American Sign Language (ASL), start by using your dominant hand in the "Y" handshape. Place it slightly in front of and above your shoulder, with the palm facing inward. Wiggle your wrist back and forth. Next, change your dominant hand to a flat '5' handshape (fingers together). On your non-dominant hand, also form a flat '5' handshape at chest level, with the palm facing upward. Place the palm of your dominant hand against the palm of your non-dominant hand. Then, flip your dominant hand up and down (with the palm changing to face upward) and smoothly sweep it forward toward your non-dominant hand's fingers.