1 pkg. active dry yeast
About 5 3/4 c. regular all-purpose or unbleached flour
1/4 c. sugar
2 tsp. salt
Instant mashed potatoes (amount for 2 servings)
3/4 c. milk
1/4 c. melted butter
2 eggs
1 c. sourdough starter
1 egg white beaten with 2 tbsp. water
Poppy seed (optional)

In the large bowl of a regular or heavy-duty electric mixer, combine the yeast, 2 cups of the flour, sugar, and salt.

In a saucepan prepare 2 servings of instant mashed potatoes according to package directions using the amounts of water, milk, butter, and salt called for on the package. Then stir in the 3/4 cup milk, the 1/4 cup melted butter, eggs, and starter; stir until blended.

Add potato mixture to dry ingredients and beat for 2 minutes on medium speed, scraping bowl occasionally. Add 1 1/2 cups more flour and beat at medium speed for 2 minutes longer. With a heavy spoon, stir in enough of the remaining flour (about 1 1/2 cups) to form a stiff dough.

Turn dough out onto a board coated with part of the remaining flour and with well-floured hands, knead until smooth, about 8 minutes. Add more flour if needed to prevent dough from sticking.

Place dough in a greased bowl, turn over to grease top, cover, and let rise in a warm place until double in bulk, about 1 1/2 to 2 hours.

Punch down dough and divide in half. For round loaves, shape dough into smooth balls; then lift up and smooth each top by pulling down and pinching a lengthwise seam underneath. For braids, divide each half into thirds. Roll each piece to form a rope about 18 inches long. Place 3 ropes on a lightly greased baking sheet; pinch tops together and loosely braid, pinching ends together and tucking underneath. Repeat for second loaf.

Cover loaves lightly with clear plastic film and let rise in a warm place until almost double, about 45 minutes.

With a razor blade or sharp knife, cut 1/2-inch-deep slashes in tops of round loaves in a crisscross pattern. Brush loaves evenly with egg white mixture and sprinkle braided loaves with poppy seeds if used.