1. Preheat oven to 350°. Rub 1 lemon half on all sides of pork roast, squeezing juice from lemon. Stir together oregano, salt, and pepper; rub on roast.
2. Place roast on a lightly greased rack in a roasting pan. Separate garlic cloves (do not peel), and place around roast. Drizzle olive oil over roast and garlic cloves.
3. Squeeze juice from remaining 1 1/2 lemons into a bowl. Stir together juice and chicken broth; pour into roasting pan.
4. Bake at 350° for 3 hours to 3 1/2 hours or until fork tender. Shred pork into large pieces using two forks, if desired. Garnish, if desired.