In a medium saucepan, bring 1 3/4 cup water to a boil. Stir in couscous; cover. Remove from heat; let stand, covered, 5 minutes. Cool to room temperature.
Meanwhile, in a medium bowl combine oil, lemon juice, salt and pepper. Stir in cucumber, green onion, parsley, basil and couscous. Mix well and chill for at least 1 hour.
Line a plate with lettuce leaves. Spoon couscous mixture over leaves and garnish with lemon wedges.
