Pre-heat the oven to 350 degrees. Lightly oil a large c***erole dish. Add the en pieces. Rub the skin with the oregano, salt and pepper. Peel and thinly slice the garlic. Top the en with the garlic and lemon juice. Place some of the spices between the skin and the meat. Allow the en to sit, covered, in the refrigerator for 1 hour. Drizzle the oil on the en and bake for 50-60 minutes (or until tender and lightly brown). Baste often. Serve warm.