Duck: Pre-heat oven to 350 degrees. Open package and separate legs from the duck broth and from the duck fat. Put duck legs and duck fat in an open cast iron pan. Place pan in oven for 20-25mins. Cook until internal temp reaches 165 degrees. Remove from oven and allow to set. Add 3Tbsp water to skillet and scrape the bottom of the pan until the water evaporates. Remove from heat.
Remove skin from legs and set aside. Pull meat from the bone, shred and place in a bowl.
Add duck fat in a skillet and add skin. Cook over moderate heat until the skin is crispy. Remove from the pan, chop and add to the shredded meat.
Add onion to fat in skillet and sauté until onions are caramelized and slightly crispy. Remove from fat and set aside. Pour off duck fat and set aside.
Place 1 tortilla on work surface and spread 1Tbsp goat cheese, 2Tbsp onions, 1/2cup duck mixture & 1 Tbsp scallions on top of tortilla. Lay another tortilla on top of the scallions.
Brush nonstick skillet with ½ tsp of the reserved duck fat over moderately high heat until hot but not smoking. Cook quesadilla turning once, until golden, about 6 mins.