Dry the baguette in advance or dry in the oven at 300F/150C for 10-15 minutes until dry, turning occasionally.

Preheat oven to 400F/200C.

Cut an X in each chestnut.

Roast chestnuts in the oven for 15 minutes.

Let cool, then peel and chop.

Alternatively, boil chestnuts for 20 minutes, drain, cool, and peel.

Chop onion and celery into small pieces.

Cut the sweet potato into small cubes.

In a saucepan, melt butter (or heat olive oil) and sauté sweet potato, celery, and onion until soft but not brown.

Add sage, rosemary (optional), salt, and pepper; cook for 2-3 minutes.

Add 120 ml (1/2 cup) broth, simmer, and cook for 5-7 minutes until sweet potatoes are soft and broth is absorbed.

Put bread cubes in a bowl and moisten with about 120 ml (1/2 cup) broth.

Add chestnuts and toss with the sweet potato, onion, and celery mix.

Preheat oven to 350F/180C.

Spread in a casserole dish.

Add more broth if desired for a more moist stuffing.

Cover with foil and bake for 25 minutes.

Uncover and bake for 25-30 minutes until browned on top.