In a bowl whisk together flour and salt. Whisk in 1 cup seltzer, whisking until smooth, and let batter stand 10 minutes. If necessary, thin batter with enough remaining seltzer to reach consistency of crepe batter.
In a deep fat fryer, or heavy saucepan, heat vegetable oil to 375 degrees. Working in batches, dip vegetables in batter, shaking off excess. Fry until golden brown. Remove with slotted spoon or spider to sheet lined with paper towels to drain.
Wine suggestion: Champagne Pol Roger