If you have time, soak mung bean in water for 4-6 hours or overnight. You can skip soaking, but you will need to increase cooking time.

Wash and drain mung bean. Add salt and mix well. Set up a steamer and steam for about 15 minutes or until mung bean is soft. If you don't soak the mung bean in advance, steam for longer and add a couple teaspoons of water to the mung bean when steaming.

Mash or process mung bean finely in a food processor. In a pan over medium low heat, add olive oil and transfer mung bean to the pan. Add sugar, coconut milk and shredded coconut. Mix well to combine into a mixture which you can squeeze and form balls easily.

Use a little over 1/2 tablespoon of filling (tightly packed) to make a ball of filling. You can make about 25 balls. Set aside.

In a mixing bowl, add glutinous rice flour and mix in salt. Add lukewarm water, mix to combine and knead for a couple of minutes into smooth dough. (If mixture is too wet, add a little more flour. If mixture is too heavy and dry, add a small amount of water.)

Divide the dough into 25 equal pieces. Lightly dust your hands with flour. Roll each piece between your palms to form a small ball of dough. While you work through the dough, cover the portion that hasn't been used with damp towel to prevent it from drying.

Flatten the ball of dough with your hand into a round with 2'' - 3'' diameter. Place a ball of filling in the center, gently wrap the the dough tightly around the filling: use your fingers to stretch and wrap, then pinch the dough at the top to seal it. Roll the ball between your palms to smooth the outside and form round shape.

Bring a large pot of water to a boil, then lower heat to medium - medium high. Add rice balls, when they float to the surface, cook for one more minute and then transfer to an ice bath.

In a pot, add all ingredients to make the syrup. Bring to a boil then lower heat and simmer until sugar is dissolved and water has been infused with ginger scent.

Remove rice balls from ice bath and add them to the pot of ginger syrup. Simmer for 5-7 minutes.

Transfer rice balls to serving bowls, sprinkle sesame seeds, ladle ginger syrup into each bowl and serve hot.