Melt butter over medium heat in a large saucepot.

Add onions and celery. Cook until onions become translucent.

Whisk in flour. Cook for 3 minutes.

Whisk in chicken stock gradually.

Let soup simmer for 10–15 minutes until celery is tender.

Gently stir in brie cheese and allow it to melt for around 5 minutes.

Pour soup into blender. This may take more than one batch. Puree until smooth and pour into a clean pot.

Heat soup to almost simmering on medium-low heat.

Stir in milk and season with salt & pepper to taste.

Place flour, sugar, salt, and yeast into bowl (if using electric mixer, use a dough hook, or if by hand, use a wooden spoon).

Add first measure water slowly and stir.

When dough forms into a ball, take out of bowl and knead for 5 minutes.

Place dough in lightly oiled bowl & immediately flip it over. This keeps a crust from forming on bread as it rises.

Let dough rise in a warm place for 45 minutes or until doubled in size.

Divide dough in half and, on a lightly floured surface, roll pieces out to 8" x 12" rectangles.

Cut 1/2" deep slashes every 3 inches in the bread. Make sure you do not cut all the way through the dough.

Cover with a clean dish towel and let rise in a warm place for about 45 minutes or until doubled in size.

Beat together egg yolk and second measure water. Brush over the bread. Bake at 375°F for 20–25 minutes until golden brown.