In a heavy 4-quart casserole, melt oil over moderate heat. Add the salt pork dice and, stirring frequently, cook until they have rendered all their fat and become crisp and golden brown; then, with a slotted spoon, transfer them to paper towels to drain.
Rinse the chicken, pat the pieces completely dry. Skin the chicken pieces. Sprinkle them liberally with salt and a few grindings of pepper. Add the chicken to the fat in the casserole and brown it, turning the pieces with tongs and regulating the heat so that they color quickly and evenly without burning. Set the chicken aside on a platter.
Pour off all but a thin film of fat from the casserole. Stir in the onions and garlic and cook for about 5 minutes, or until the onions are soft and transparent but not brown. Stir in the paprika, then the tomatoes and bring to a boil, stirring frequently. Cook briskly, uncovered, for about 5 minutes, or until most of the liquid in the pan evaporated and the mixture is thick enough to hold its shape lightly in a spoon.
Return the chicken and pork dice to the casserole, and add the rice, peas, boiling water, saffron and 1 teaspoons of salt. Stir together gently but thoroughly. Bring to a boil over high heat, then reduce the heat to low, cover tightly and simmer for 20 to 30 minutes, or until the chicken is tender and the rice has absorbed all the liquid. Stir in the parsley and taste for seasoning.
Cover and let stand off the heat for 5 minutes before serving directly from the casserole.