Paella

In a large casserole heat 1/3 cup olive oil and in it cook 1/2 cup grated onion for two minutes, stirring. Add the pork and chicken and saute for 5 minutes stirring. Then add garlic, tomatoes, herbs, salt, pepper and saffron. Cover and cook over medium heat about 25 minutes, stirring from time to time. Meanwhile, steam the mussels and clams in 1 cup water until they open, about 5 minutes. Discard any that do not open. Reserve the mussels, clams, and cooking liquor and discard the shells. Strain the liquor. Add the green peppers and green beans or artichokes to the casserole. Cook covered 5 to 10 minutes longer. Meanwhile, heat the remaining olive oil in a paella pan and cook the remaining 1/2 cup grated onion 1 minute. Add the rice and cook stirring until all the grains are coated, 8 to 10 minutes. Add the mussel and clam liquor plus 7 cups water to the casserole. Bring to the boil. Slowly pour the bubbling sauce over the rice. Then slide the remaining contents of the casserole evenly over the sizzling rice. Add the red peppers, shrimp, chorizo slices, mussels, and clams. Stir once. Cook uncovered over brisk heat until the liquid is absorbed and the rice is tender, about 20 minutes. Rotate and shake the pan from time to time to cook the rice evenly. Allow the contents to rest 5 minutes before serving. Serve directly from the pan with the lemon wedges.