Trim any skin and bones from fish, cut flesh into 1x3-inch strips.
Spread fish strips in a shallow non-metal dish and sprinkle with lemon juice, salt and pepper. Set aside.
Put cilantro, chili, garlic and water in a blender or food processor fitted with the metal blade and process until smooth, frequently scraping down mixture.
Squeeze out excess liquid from paste, place in a shallow dish and stir in yogurt.
Heat oil in a deep-fryer to 350°F (175°C) or until a 1-inch bread cube browns in 65 seconds.
Drain fish and pat dry with paper towels.
Dip the strips in yogurt mixture, coating them all over and fry a few at a time 2 to 3 minutes, until golden brown.
Drain on paper towels, then serve at once, garnished with lemon wedges and cilantro leaves.