Cat vomited or regurgitaed up mucus

I give my cats cat grass as a treat like I usually do and my cat rarely vomits after eating the grass. But today he vomited a minute after eating it, and on the floor was a pile of thick mucus with all the grass stuck in it. I could tell it was mucus and not saliva because when I wiped it up it moved like a giant jelly mass, gross.

It had a slight yellow tint to it, but if you didnt look closely you wouldnt be able to tell that.

Does this mean my cat is sick or is it normal for them to cough up mucus after eating grass?

From how it sounds, my Willow does the exact same thing! He eats so much grass, so quickly, and doesn't properly chew it! He does end up throwing up grassy type mucus. (I remember my RB Disco used to do the same thing, even though she was indoor/outdoor)

I have also chatted to my vet about it and she says that it's a regular thing as many cat's will over eat it when it is in limitation. (Willow has done this when it is in abundance though )

I wouldn't be too concerned about it unless it contains more than grass - by the way, was the grass pretty whole? - as it does help bringing up unwanted nasties, which we may not realise that they have (especially with the heat of 'summer' rolling in.

I would keep an eye on him just in case though

ETA: was the sick motion appear easy or strained?