What kind of iceberg can be eaten completely in one meal?

A simple invention, yet so complex. Millions of people question daily How large of a team is required To remove and to install me.

I'm long and green, a garden delight, But some say my shape is a bit impolite. I'm cool in a salad, a refreshing bite, But what am I, causing such lyrical plight?

I'm an unusual mercenary. Some call me a Ninja, but that's one of many labels. I don't charge by the day, You can just buy me once. I have no legs so you need To bring me your victims And drop them into my knives. I'll keep cutting and slashing until you tell me to stop. Pour out the remains into your glass. Yummy!

None save Lestat, et al., can escape me.