COMBINE 1 cup all-purpose flour, whole wheat flour, undissolved yeast, sugar, 2 tablespoons onions, parsley, poultry seasoning and salt in a large bowl. Heat water and butter until very warm (120° to 130°F). Stir into flour mixture.
BEAT 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Stir in remaining all-purpose flour to make stiff batter.
COVER and let rest 10 minutes. Turn batter into greased 1-1/2 quart casserole. Smooth top of dough in casserole with floured hands. Cover.
LET RISE in warm, draft-free place until doubled in size, about 30 minutes. Brush beaten egg on loaf. Sprinkle with remaining onion and celery seed.
BAKE at 375°F for 35 minutes or until done.* Remove from casserole; cool on wire rack.
* Bake at 350°F if glass casserole is used.