Wipe chicken with damp paper towel. In large skillet, heat olive oil and brown chicken, 5 pieces at a time, until golden. Remove as it browns and set aside. Add pork cubes to skillet. Brown well on all sides. Remove and set aside. Add onion, garlic, pepper and oregano to drippings in skillet. Stir 5 minutes until onion is golden. Add salt, rice, saffron and cook stirring about 10 minutes. Meanwhile in another skillet brown sausages on all sides, about 10 minutes. Drain sausages and discard fat. Cut sausages into bite size pieces. Place chicken, sausage and pork in roasting pan. Heat oven to 375 degrees. Add tomatoes, bay leaf, and chicken broth to rice mixture and bring to a boil. Add shrimp. Spoon evenly over chicken, pork and sausages in pan. Bake, lightly covered with foil, 1 hour. Sprinkle peas over top without stirring (if mixture seems to dry add 1/2 cup water) and bake 20 minutes longer. To serve, turn onto round heated platter or paella pan. Garnish with pimento and lemon wedges.