Sift the flour, salt, pepper and 2 teaspoons of the sugar into a large bowl. Make a well in the center and pour the eggs into it. Stir just enough to combine the ingredients.
In a medium skillet set over moderate heat, stir-fry the pork, scallions, and two-thirds of the garlic in the sesame oil for 8-to-10 minutes, until the pork is no longer pink; do not brown the meat. Add the asparagus, toss for 1-or-2 minutes over moderate heat, then allow the mixture to cool to room temperature.
In a separate bowl, combine the remaining ingredients, except the vegetable oil, to make a dipping sauce.
When the pork mixture is cool, stir it into the reserved batter. Heat the vegetable oil in a large skillet over moderately high heat until ripples show on the skillet bottom.
Half fill a 1/4-cup measuring cup with the batter and drop the batter into the hot oil, evening up the ragged edges of the pancake. Add 3 more pancakes to the skillet, smoothing the edges as before, and brown them for 1-to-1 1/2 minutes per side. Drain them on paper towels, then keep them warm on an uncovered platter in a 250F oven.
Fry the rest of the pancakes, adding more vegetable oil to the skillet if needed. Serve the pancakes hot with the dipping sauce.