Preheat frying oil to 375 degrees.
For the batter, combine and sift the flour and salt into a mixing bowl. Make a well in the center. Pour in 2 tablespoons olive oil and gradually beat in the water to make a smooth, thick batter. Cover and refrigerate for 1 hour. Before using, beat the egg whites until firm. Lightly fold beaten egg whites into the batter.
Thoroughly rinse all the seafood and drain off excess water. Dip the assorted seafood and vegetables in the prepared batter and shake off any excess. Fry in hot oil until crisp and golden. Lift out and drain on paper towels.
Fry the fresh herbs and then drain. Sprinkle fried seafood with salt and divide onto 4 serving plates. Garnish with the fried herbs and lemon wedges. Serve immediately with tartar sauce or spicy aioli.