Soupe aux marrons (Chestnut soup) - Untested

French Country Cooking by Elizabeth David, pg 39
https://www.femmesplus.fr/recettes-potage-a-la-puree-de-perdrix.20787.722.html

From the Pyrenées

2 slices of crusty bread (about 1 cup, cubed)
2 Tbsps butter
40 chestnuts
6-8 cups of Chicken stock
1 Roast Partridge (or 18oz of cooked chicken or pheasant)

To make the croutons:

1. Over medium heat melt the 2 Tbsps of butter in a small pan (level of butter should be 1/4 inch) and allow it to heat up completely so that when a cube of bread is put in, it will quietly sizzle.
2. Add the bread cubes and fry, stirring constantly so they brown evenly, about 30 seconds to 1 minutes. 
3. Burns easily!
4. Strain off the extra fat. 
5. With a slotted spoon remove the croutons and divide croutons between two plates.

To make the soup:

1. Cut an X at the top of each chestnut and dry roast them in a 300F oven for 15 minutes. Remove the tough shell and peel away the thin inner membrane to reveal the creamy flesh (do this while still quite warm or it all becomes brittle and difficult to work). 
2. Cook the chestnuts in the stock for 2 hours.
3. Meanwhile, pound the meat in a mortar or pass through a meat grinder or use a food processor to turn into a paste.
4. Once the chestnuts are cooked, add the meat, mix thoroughly and pass through a sieve.
5. Return the soup to the pan and bring to a boil to reheat.
6. Serve with the fried croutons on top.