Heat oil in large skillet. Add cut chicken and brown all over. Add water, cover and simmer 30 minutes. Remove chicken and set aside. In the same skillet add onion and garlic. Saute until clear. Add rice and saffron. Cook over low heat till rice is light brown. Add chicken broth, bring to a boil, cover, reduce heat and simmer about 17 minutes. Toss in peas. Arrange rice, chicken, shrimp, sausage and clams in layers of a large oiled casserole dish. Bake at 180ºC or 15-20 minutes. If using clams, bake until they open.