Place the chicken pieces in a pot and cover with boiling water. Add the leeks, salt, and parsley. Simmer for 2 ½ hours, or until the chicken is no longer pink in the middle. Remove the chicken pieces with a slotted spoon.

Add the rice to the pot. Cook for 20 minutes, or until the rice is tender.

In a small bowl, mix together the butter and flour. Add this mixture to the pot, blending well.

Add the prunes and some of the chicken meat, cut into bite-sized bits. (Reserve the rest of the chicken for another dish.) Serve immediately.