X-Men Origins: Wolverine

When you first fight a guy who shoots a rocket at you in level 3(when you get your claws) all you have to do is block(LT) right before the missle hits you to shoot it back at the person

I unlocked this in Chapter 1: Origins, Checkpoint "A Frosty Reception"

Where the game actually prompts you to reflect the projectile from a Grenadier standing up high on a ledge above and to the right of 2 other enemies.

As a fore mentioned block (LT) just before it hits (Took me 3 attempts but if you stand still the other 2 wont attack you until you have succeeded in reflecting the grenade and killing the Grenadier)