In a saucepan, combine the chicken stock, whole onion and the crushed saffron threads. Cover the pan, and simmer over low heat while you prepare the rest of the ingredients.

Peel and devein shrimp. Wash the clams. Rinse the chicken in cold water and pat dry.

Slice the chorizo into 1/8" discs. Place in a paella pan or skillet, and cook over medium heat until fat is redered. Remove with slotted spoon, and reserve. Wash or wipe out the skillet. Saute shrimp in 1 tablespoon olive oil until pink; remove and reserve.

Wash or wipe out the pan. Salt and pepper chicken pieces. Brown chicken in 1 tablespoon of oil, turning until all sides are browned but not fully cooked. Remove from pan and reserve. If desired, remove the skin from the chicken pieces and discard.

Drain fat from pan. Add final tablespoon of oil to pan. Add onions and salt pork. Over medium-high heat, saute the mixture until onions are wilted. Add garlic, and saute about 30 seconds. Add white wine, stir and cook over medium-high heat until most of the wine has evaporated.

Remove pan from heat. Add paprika and tomato and parsley, and stir well. Return pan to heat, and cook until mixture thickens. Add rice, and stir until rice is coated with tomato mixture.

Remove whole onion from chicken stock. Add chicken stock and saffron to rice mixture. Raise heat to high; stir and add chicken pieces, shrimp, clams, chorizo, bay leaf and lemon juice. Gently stir ingredients.

Cover and cook over low heat until the rice has absorbed the liquid and the clam shells have opened, about 25-30 minutes.

Five minutes before the end of cooking time, sprinkle top of paella with peas. Cover and continue cooking. Garnish with pimiento.