Remove meat from the lobster. Shell and devein shrimp. Scrub mussels and clams. Cut chicken into medium sized serving pieces. Combine oregano, peppercorns, garlic, salt, two Tbsp of the olive oil and the vinegar and mash with back of spoon or with a mortar. Rub chicken with the mixture. Heat remaining olive oil in a deep, heavy skillet and brown chicken lightly over moderate het. Add ham, chorizo, salt pork, onion, green pepper, coriander and capers. Cook ten minutes over low heat. Add tomato sauce and rice and cook 5 minutes. Add boiling water, saffron and shrimp. Mix well and cook rapidly, covered, until liquid is absorbed, about 20 minutes. With a large spoon, turn rice from top to bottom. Add lobster meat and peas; cover and cook 5 minutes longer. Steam mussels and clams in a little water until their shells open. Heat the pimientos and drain. Us the mussels, clams and pimientos as a garnish.