Toasted sesame seed or -poppy seed In a large bowl thouroughly mix 1 cup flour, salt, sugar and undissolved yeast. Add margarine. Gradually add tap water to dry ingredients and beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Add 1/2 cup flour. Beat at high speed 2 minutes, scraping bowl occasionally. Stir in enough additional flour to make a soft dough. Turn out onto well floured board. Divide dough into 16 equal pieces. Roll each piece of dough into a rope, 18 inches long. Cut each rope into three 6-inch ropes. Place on greased baking sheets, rolling to grease all sides of dough. Cover with plastic wrap. Freeze until firm. Transfer to plastic bags. Freeze up to 4 weeks. Remove from freezer, place on ungreased baking sheets. Cover; let stand at room temperature until fully thawed, about 30 minutes. Let rise in warm place, free from draft, until doubled in bulk, about 15 minutes. Brush with combined egg white and cold water, sprinkle with seeds. Bake at 375 20 to 25 minutes, or util done. Remove from baking sheets and cool on wire racks.