Start a large stock pot of water to boil for ravioli.
For the Filling.
Rinse duck and pat dry. Season inside and out with salt and pepper. Cut vegetables into wedges. Stuff duck cavity with vegetables and squeeze juice of orange into cavity. Place duck on roasting rack. Roast for 15 minutes on 450. Reduce heat to 350°F and cook until thermometer reads 160 in thigh.
Remove meat from bone, reserving bones to make a secondary stock. (this could be used in place of the reserved mushroom stock as suggested for the ragu-it would give greater depth to the dish without the mushrooms overpowering the delicate ravioli).
Shred or dice very fine the duck. Moisten with meat with the juices from roasting pan if necessary.
For the Pasta Dough.
Mix dry ingredients, eggs, water and salt in a bowl. Knead dough until it is silky soft (about 25 minutes by hand).
Roll out on a floured surface to ¼ inch thickness. If dough is sticky, sprinkle with flour.
Using a biscuit cutter or small glass, cut 3-inch circles from the dough.
Place a spoonful of the mixture in the center of the circle and top with another circle of dough.
Crimp the edges with a fork, being sure to completely seal the ravioli. If needed, moisten the edge of the bottom circle with cold water before crimping the top circle over the filling.
For the Ragu.
While duck is roasting, place dried wild mushrooms in heat-proof container and add boiling water to cover. Allow to stand until mushrooms are reconstituted, about 1 hours or so. Drain mushrooms, reserving liquid. Chop mushrooms into bite-sized pieces. Reserve.
Add veal demi-glacé to sauté pan along with reserved mushroom liquid (be sure to strain mushroom liquid to remove any particles and/or residual dirt). Create a sauce from the demi-glace making sure it isn’t too thin or too thick. Add mushrooms to the sauce. Adjust seasonings as needed.
For the Ravioli.
Make ravioli by filling with desired amount of duck, sealing with egg wash (or water) and removing all air bubbles from each ravioli.
Cook ravioli in boiling water until al dente, about 6 minutes.
Drain ravioli, reserving some of the pasta liquid. Quickly add ravioli to ragu. Gently toss to coat ravioli with ragu. Add additional cooking liquid from pasta if necessary. You don’t want this too dry.
Dish into pre-heated, large shallow rimmed bowls. Place a 1/4-1/3’ slice of Foie Gras on top of ravioli.