Mix flour, cornstarch, salt, and water into a thin, smooth batter
Let the batter rest briefly
Heat a nonstick pan or griddle over low heat
Transfer the batter into a piping bag or squeeze bottle
Pipe very thin strands in a lacy pattern onto the hot surface
Cook only until the strands set and dry
Lift the cooked strands carefully
Repeat until all batter is used
Cool the strands completely
Separate and fluff the strands gently
Use immediately or store dry until needed