1. Cook gnocchi according to package directions and set aside.
2. Heat pan over medium heat. Add oil and sauté shallots and mushrooms until nicely browned and water has evaporated. Add in garlic, salt, pepper and herbes de Provence. Cook until fragrant (about one minute).
3. Mix in flour and coat mushroom mixtures well. Add in wine, stock, and chestnuts. Cook for another five minutes, then add in the gnocchi.
4. Remove from heat and mix in milk substitute. As gnocchi cools, sauce will thicken, and you may have to add additional milk substitute.