In a hot saute pan, render the andouille for 1 minute. Add the shallots, garlic, and yellow onions. Saute until soft, 2 to 3 minutes. Remove from heat and add the balsamic vinegar. Transfer to a mixing bowl and whisk in 1/2 cup of the olive oil. Season with salt and pepper, to taste.
In a food processor, combine the pecans and 1/2 cup of the flour. Pulse until finely ground; be careful not to overprocess or the mixture will become a paste. Season with the Essence.
Preheat the oven to 400 degrees F.
In a shallow bowl, season the remaining flour with salt and pepper. Season the egg wash and duck legs with salt and pepper. Dredge the legs in the seasoned flour. Dip each leg in the egg wash, letting the excess egg wash drip off. Dredge the legs in the pecan-flour mixture, coating the leg completely. In a large saute pan, heat enough olive oil to come 1/3-inch up the sides of the pan. When the oil is hot, lay each leg into the hot oil. Pan-fry the legs until golden brown, about 3 minutes on each side. Remove the pan from the heat and transfer the legs briefly to a paper towel-lined plate to blot any excess oil. Transfer legs to a small baking sheet. Place the baking sheet in the oven and cook the duck legs until heated through, 6 to 8 minutes. In a large mixing bowl, combine the spinach and red onions and toss with the vinaigrette. Season with salt and pepper. Mound the greens in the center of 4 plates. Lay 1 leg on top of each serving of greens. Garnish with black pepper.
Emeril's ESSENCE Creole Seasoning (also referred to as Bayou Blast):
Combine all ingredients thoroughly.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch, published by William and Morrow, 1993.