Begin by making the water roux. Whisk together Water (125 milliliter) and Bread Flour (25 gram). Whisk until smooth. Cook on medium heat and bring to a gentle boil. Continue to stir until smooth and thickened. Set aside.
Put Dark Brown Sugar (55 gram), Salt (1 teaspoon), Bread Flour (325 gram), Milk Powder (1 tablespoon), Instant Dry Yeast (1 1/2 teaspoon), and Butter (2 tablespoon) in a clean working surface. Make a well and add the 120 grams of the water roux, Milk (125 milliliter) and Egg (1) into the well.
Knead until it becomes gluten develops and it becomes a dough. Gently roll in half of the nuts and seeds - Sultanas (40 gram), Flaxseeds (15 gram), Pumpkin Seeds (20 gram), and Walnut (40 gram). Cover with wet towel until it doubles in size, about 45-60 minutes.
When ready, transfer the dough to clean, floured working surface. Gently begin to deflate the dough and squeeze all the air out. Divide dough into 8 portions.
Form each portion into a roll sized shape and place onto a floured baking pan. Cover with cling wrap and rest for another 45-60 minutes or until the rolls double in size.
Seperate the Egg (1) white from the yolk.
Preheat an oven to 180 degrees C (350 degrees F).
Before baking, brush some of the egg white on top of each roll. Mix the remaining Sultanas (40 gram), Flaxseeds (15 gram), Pumpkin Seeds (20 gram) and Walnut (40 gram) together, and sprinkle the mixed seeds and nut mixture on top of the rolls.
Bake for about 25 minutes until golden brown. Transfer to rack and let them cool down before enjoying.