Chinese Leek With Sea Cucumber

Chinese leek is in the season again. Every year in between year end to chinese new year period, there will be plenty of chinese leek for sale. What are the main concern to look out for when choosing leek? The bulk muz be big & fat, bit of reddish & purplish below, greenish leaves on top.
Since its in the season now, y not eat it 1st even though i still get to eat them during chinese new year.

Ingredients;
5 stalks leek
120g pork belly
1 small pc tau kua
Some sea cucumber
Pinch of salt
Water
Oil for frying

Method;
-Peel off the outer skin of chinese leek, wash clean. Cut them diagonally into 1 cm apart.
-Cut pork belly & tau kua into small strips, sea cucumber into slices.
-Heat some oil in wok, pan fry tau kua until golden brown, drained.
-Fry pork belly with 1 tbsp oil till pork change colour.
-Stir in leek, fry for 3 mins or until soft.
-Add seasonings, tau kua, sea cucumber & water.
-Cover with lid for about 8 mins or when sauce dries up.
-Serve with plain rice.
-Enjoy!