After saving the town, you'll see a quest giver outside the church saying his chickens have flown the coop and are running loose in his home. Your task: to put those chickens back in their coop!
Look for the door with Casa de Pollo above and enter to find indeed a room full of chickens!
The chicken coop you need to herd them into is on the far right. It's open (you can jump in yourself if you want to test ;>), but the chickens aren't going to go in voluntarily.
The way to encourage them is to panic them.
Hitting the chickens a few times would turn them red and cause them to go into a frenzy.
At that point, they'll rush around and won't care as much where they're going and easily fall right into the coop.
The tricky ones are at the bottom floor of the house.
Chickens can't jump, so it's up to you to throw them back up. If you remember your battle in the church, hitting enemies enough times would give you a triangle prompt that allows you to throw them.
Do the same with the chickens. When you press triangle and see the arrow, move the left stick up and the arrow will point up as it charges. You will then throw the target chicken up to the top floor where it will continue its panicked run into the coop.
The panic will wear off. So if somehow a chicken doesn't run itself into the coop, hit it again.
Once all the chickens are in, Juan will glow white and do a victory pose.
Go outside and the questgiver will be waiting for you.
Talk to him and earn your trophy! Congratulations!