Mix the flour and 150ml water in a saucepan over low heat until thickened into a paste.
Cook the roux for one more minute then cool to room temperature with cling film on top.
Sift dry ingredients into a bowl and stir in yeast, eggs, butter, chopped chilli, and roux.
Add 225ml lukewarm water gradually to form a soft dough.
Knead the dough on a floured surface for 10 minutes.
Place dough in an oiled bowl, cover, and let rise in a warm place until doubled.
Knock back the dough and knead in the chocolate chips.
Divide into 12 balls and place on a greased baking sheet to rise for 20 minutes.
Preheat the oven to 190°C.
Brush buns with egg wash, top with sliced chillies, and bake for 12 minutes.