Cut the tofu into six slabs crosswise. Blot well between clean tea-towels or several layers of paper towel (or use a tofu press ahead of time). Cut each slab in half to make two squares. Finally, cut each square on the diagonal to make triangles.
Heat the oil and soy sauce in a wide skillet. Arrange the tofu triangles in a single layer and sauté on both sides over medium-high heat until golden. Cook in batches if need be.
Drizzle the satay sauce and sriracha into the skillet and stir gently with the tofu triangles, turning them over a few times until nicely glazed.
To serve, line a platter with shredded lettuce. Arrange the tofu triangles over it, then sprinkle with dried hot red pepper flakes.
Serve at once, passing around the bottle of peanut satay sauce and extra sriracha for those who would like more.