2 pounds (1 kilogram) pickled tongue
1 tablespoon imitation vinegar
small handful of pickling spice (optional)
pinch of salt
2/3 cup water
1/2 cup potato starch
oil, for frying
2 cups reserved cooking liquid, cooled
1 tablespoon potato starch
1 (6-oz./170-g.) can Tomato Paste
1/4 cup brown sugar
2 tablespoons lemon juice
1 teaspoon cinnamon
Cook the Tongue:
Place tongue in an eight-quart pot and cover with water. Add the vinegar and pickling spice, if desired. Bring to a boil over medium-high heat. Boil over low heat for an hour and a half.
When the tongue can be pierced easily with a fork, remove it from the water. Reserve two cups of cooking liquid and set aside to cool. Place cooked tongue under running water and remove the outer membrane. Allow tongue to cool as you prepare the sauce (below).
Prepare the Crepes:
This crepe batter yields 12 eight-inch (20-centimeter) crepes.
Using an immersion blender, beat eggs and salt. Dissolve potato starch in water and blend into the egg mixture until completely smooth.
Lightly grease an eight-inch (20-centimeter) frying pan. Heat over medium-high heat.
Add three to four tablespoons of batter to the center of the frying pan. Lift up and swirl the pan until the bottom is coated with batter. Return to heat and cook until edges begin to separate from the pan’s edge and the crepe appears firm. Flip crepe and cook an additional 15 seconds. Turn crepe out onto a prepared paper towel. Allow to cool slightly.
Note: You can stack the crepes once they’re cooled.
Prepare the Sauce:
Pour the reserved cooking liquid into a large frying pan. Add potato starch. Place over medium heat and whisk continuously until the mixture begins to thicken. Add in tomato paste and stir until completely combined. Mix in remaining ingredients. Remove from heat.
Slice tongue thinly, then sliver or dice finely. Transfer to a large bowl. Mix one and a half cups of cooked sauce into the diced tongue.
To fill: Place two tablespoons of the tongue mixture on the bottom part of a crepe. Fold the bottom over the mixture. Fold both sides towards the center. Roll upwards till completely closed and lay seam-side down on a parchment-lined baking sheet.
Fill a large frying pan with one inch (two centimeters) of oil. Heat to medium-high heat. Fry spring rolls until golden on all sides, about two to three minutes.