Combine the pork, pork fat, Essence, paprika, garlic, black pepper, salt, file, chili powder, red pepper, and cumin in a large bowl and mix well. Pass through a food grinder fitted with a coarse die. (Alternately, transfer in 2 batches to a food processor and process until finely ground.) Transfer to a large bowl, cover tightly with plastic wrap, and refrigerate overnight.
To test the seasoning, heat 1 teaspoon oil in a small skillet, and cook about 2 teaspoons of the mixture. Adjust seasoning, to taste.
Using the sausage attachment on a mixer, stuff the meat into the casings, if being used. Twist and tie off to make 4-inch sausages. Alternately, shape into patties.
Preheat a home smoker to 250 degrees F. Smoke the sausage for 1 1/2 hours. Remove from the smoker and use as desired.
Yield: about 2 pounds