[ there's a pause, at the question, before inej offers a smile and holds out the pieces of flint to ruki. ]

Sure; it's easier than it looks.

[ and inej pulls the drier brush closer, to set it up in a manner that'll be easy to catch. ]

Strike the rocks together to create a spark . . . it may take a few tries, but try to catch the grass and smaller brush on fire. And blow on the embers, to create a flame.