In a large pot of boiling salted water, cook the millet, stirring occasionally, for 15-20 minutes, until tender. Drain well, then spread on a baking sheet and allow to cool.
In a small bowl, whisk together the tamari, rice vinegar, sugar, sesame seeds, Sriracha sauce, and 1/4 of the scallions. Set aside.
In a medium bowl, whisk together the eggs, buttermilk, cornstarch, sesame oil, and salt. Fold in the remaining scallions and the millet.
Heat 2 tablespoons of the sunflower oil in a large, well-seasoned cast iron skillet or non-stick skillet. Work in batches to make pancakes. Add heaping spoonfuls of the millet batter to the skillet, and press to 1/4-inch thickness. Cook about 3 minutes per side, until golden brown, and transfer to a paper towel-lined plate.
Serve with more sliced scallions on top, with reserved dipping sauce.