Put steamed purple sweet potato, salt and coconut milk into the blender. Blending until smooth. Then whisk the eggs, sugar and coconut sugar until dissolve and mix well.

Put the blended purple sweet potato and mixed egg into the wok. Skim over medium heat, continue stir until sticky. Add steamed purple sweet potato cubes. Add fried shallot oil, stir well. Scoop into the mold.

Bake at 180 degrees celsius for 45-60 minutes. Sprinkle fried shallot before serve.