Place the fennel seeds, coriander and cumin in a small frypan. Cook, shaking the pan occasionally, for 3 minutes or until aromatic. Transfer to a mortar and pestle to pound until a rough powder. Transfer to a large mixing bowl.
Use the same mortar and pestle to pound the onion, garlic, ginger, lemongrass and salt to the mortar and pound to a rough paste. Transfer to the bowl with the spices. Add the turmeric mix together. Add the chicken and mix well until well combined.
If time allows cover and marinate in the fridge over night. Otherwise , continue to next step.
Add the egg and cornflour to the chicken and mix to combine.
Fill a saucepan or wok to about 1/3 full with the vegetable oil. Heat over medium heat or temperature 165C or when a wooden spoon dipped into the oil forms small little bubbles. Cook the chicken in batches until golden and cooked through (15 minutes) depends on the size of the chicken pieces. Drain the pieces on paper towel on a tray. Sprinkle with sea salt and serve.