You must soak dried chestnuts overnight. Clean the soaked chestnuts, removing any skin and any imperfections, rinse.
Cook in pressure cooker with enough water to cover, for 1 hour
Separately cook the millets in 2 cups of water, as soon as it comes to a boil, lower the heat and place a flame deflector under the pot, or use a double boiler (millet tends to burn easily), cook for 20 minutes.
In a skillet heat the olive oil, sauté the onions and garlic, add the yams, carrots, celery and stir. Cover and cook on low heat, stir often.
Separately crumble the chestnuts and mix them in with the millet.
Mix the tahini with 3 tablespoons of hot water, and liquefy.
When the sautéing vegetables are tender, add the millet mixture to it. Then add the soy sauce and tahini and mix well.
Sauté and stir for 10 minutes more.
Can be served hot or cold.