Mustard seeds are kitniyot so Ashkenazi Jews aren't supposed to eat mustard. Some Sephardi and Mizrachi groups will eat mustard though.
we eat the seed of the mustard
You can eat processed mustard as a condiment, seeds, oil, and even the greens.
People who like the flavor of mustard as well as the flavor of garlic eat garlic mustard.
With fork and mustard
We eat the ground seeds of the mustard.
Eat it with Mustard on it.
Nothing, they are a seed.
No, it can't.
we eat the seed of the mustard
It depends on their diet.
Mustard is made from mustard seeds. If you buy coarse ground mustard you can see them, or you can buy whole mustard seeds at the store. The seeds are dried and then ground up and mixed with vinegar to make the condiment we typically use.