In a large bowl, combine 5 cups flour, sugar, yeast, and salt.

In a small saucepan, heat sour cream and 1/4 cup water to 120-130°F.

Add the heated sour cream mixture to the dry ingredients and beat on medium speed for 2 minutes.

Add 2 eggs, onion soup mix, softened butter, baking soda, remaining warm water, and 1/2 cup flour.

Beat for 2 minutes longer. Stir in enough remaining flour to form a firm dough.

Turn the dough onto a floured surface and knead until smooth and elastic (about 6-8 minutes).

Place dough in a greased bowl, turning once to grease the top. Cover and let rise in a warm place until doubled (about 1 hour).

Punch the dough down and turn it onto a lightly floured surface.

Divide the dough into six equal portions and shape each portion into a 15-inch rope.

Place three ropes on a greased surface and braid them. Pinch the ends to seal and tuck under.

Repeat with the remaining three ropes. Cover and let rise until doubled (about 1 hour).

Beat egg and cold water together to make an egg wash. Brush the egg wash over the dough and sprinkle with sesame seeds.

Bake at 350°F for 35-40 minutes, or until golden brown.

While the braid is baking, saute diced onion in 1 tablespoon butter in a large skillet until golden brown.

Add minced garlic to the skillet and cook for 1-2 minutes longer, or until the garlic is tender.

In a large bowl, beat cream cheese, onion mixture, fresh parsley, and remaining softened butter until creamy.

Serve the bread warm with the cream cheese mixture.