Boil chicken breasts in water seasoned with salt, poultry seasoning, onion, and celery until tender. Cool, de-bone and tear into bite-size pieces. Set aside. Saut onion in butter and add remaining ingredients, except asparagus, chicken and almonds. Simmer sauce until the cheese melts. To assemble, place a layer of chicken in a large casserole, a layer of asparagus and a layer of sauce. Repeat layers, ending with sauce. Top with almonds. Bake at 350 degrees until bubbly. Do not add liquid even if it looks dry. If large breasts are used, this will serve 8-10.