GD Buns with Egg Potato and Tuna Filling

GD here means gelatinised dough. The original recipe was from Sonia of Nasi Lemak Lover.   This is a good bun recipe which I have tried many times with various fillings.  Here, I'm using the same bun recipe with     another savoury filling, Egg, Potato and Tuna Filling.

Ingredients for Gelatinized Dough
100 gm bread flour

70 ml hot boiling water 

1. Mix together into a rough dough using a pair of chopstick.  Cover dough with cling film [I used a plastic airtight container] and leave dough to cool in the fridge for 1 hour and up to 48 hours [2 days].

To Prepare Basic Sweet Bread Dough
1 portion of the gelatinized dough
300 gm bread flour
100 gm plain flour
80 gm castor sugar
20 gm milk powder [I used 1 tbsp skimmed milk powder]
1 tbsp yeast
1/2 tsp salt
1 cold egg
175 ml cold water [I used only 160 ml because I used 1 large egg]
60 gm cold butter - cubed [I used 50 gm]
egg glaze [I used milk] 
1. Mix sweet bread dough ingredients [except butter] with gelatinized dough in a mixer with dough hook. Knead on medium speed for about 10 minutes till soft and smooth [the dough is quite wet but it is alright] then add in butter.
2. Continue to knead for another 10 - 15 minutes until dough is soft, smooth and elastic [the dough should be ready if it does not stick to the fingers when touch]. 
3. Shape into a round ball with floured hands, cover and leave to rest for 15 minutes or until double in size. 
4. Punch down dough. Divide dough into 16 equal portions [quite big buns] or 20-24 portions [smaller buns]. 
5. Shape into balls, then roll each ball on a floured board into circle. Add the filling, pinch the seam to seal the edges and roll/shape into any shapes preferred. Place bun on cupcake paper casing or parchment paper. 
6. Leave to rise for 45 minutes in the oven. Remove them from the oven after 40 minutes before preheating oven. Brush with beaten egg glaze or milk and sprinkle with some sesame seeds. 
7. Bake in preheated oven at 180 degrees C [middle shelf] for 15 minutes. Turn to top heat for another 1-2 minutes just to brown buns [buns look pale if using milk].
8. Remove to cool on rack immediately before storing. 

Notes

You can prepare the dough until Step 2, keep in a durable plastic bag, tied up and refrigerate until later use.  Thaw  dough to room temperature before shaping for baking.

Egg, Potato and Tuna Filling

[enough for making 12 - 16 buns]
1 can tuna in mayonnaise [if using tuna flakes in brine - drain away the liquid and add 3 tbsp mayonnaise]
1 hard boiled egg - diced
1 potato - steamed and mashed
some dried Italian mixed spices/herbs 
some pepper and salt to taste

1. Prepare and mix all the ingredients together.  Refrigerate before using.