Cuban Shredded Pork

I really like this recipe. It's easy, and even the cold leftovers taste great. The original recipe can be found here. I imagine this would also be good with chicken or turkey instead of the pork.1 1/2 pounds boneless pork loin1 cup waterjuice of 1 lime8 black peppercorns3 cloves crushed garlic1 tsp. dried thymea couple pinches of salt2 tbsp. olive oil1 large onion, halved and thinly sliced4