To make the pancakes, sift the flour into a bowl and add pepper. Make a well in the centre. Beat the eggs, milk and 1/3 cup water together and pour into the well; whisk in the flour to form a smooth batter. Cover and leave to stand.
To make the filling, mix together the tomato puree, 1 tablespoon oil, the lemon rind and juice, vinegar, sugar and honey in a bowl. Add the chicken and toss to coat the strips.
Heat a wok and add another tablespoon oil. Add the onion and stir-fry for 5 minutes or until softened. Add the zucchini and stir-fry for 3 minutes. Using a slotted spoon, remove the vegetables from the wok and set aside. Reheat the wok, then add the chicken mixture and stir-fry for 3–4 minutes or until cooked. Return the vegetables to the wok. Toss together, then remove from the heat and set aside.
Heat a 20cm nonstick frying pan and grease with a little oil. Pour in some batter and tilt the pan so the batter spreads evenly; tip any excess back into the bowl. Cook the pancake over medium-high heat for 2 minutes, then loosen the edges, flip it over and cook for 30 seconds. Slide the pancake onto a plate and cover with greaseproof paper. Repeat with the remaining batter to make 8 pancakes. Cover with foil and keep warm over a pan of simmering water. Reheat the filling. Add the bean sprouts, sesame seeds and soy sauce, and stir-fry for approximately 1–2 minutes until everything is hot. Fill the pancakes, fold into quarters and garnish with the spring onions. Serve with extra soy sauce to sprinkle.