Preparation for black hamburger buns (to prepare in advance)
• In a blender, mix the water, milk, yeast and sugar. Let rest for a few minutes while the yeast proofs. Meanwhile, beat one egg with the squid ink in a separate bowl.
• Add the squid ink mixture to the yeast. Then add both flours and the salt. Mix everything together and add the butter bit by bit. Mix on low speed for eight to ten minutes. The dough should remain a bit sticky.
• Form the dough into a ball, place it in a greased pan and let it rise in a warm place. This can take one to two hours. • Once the dough has risen, line a baking sheet with baking paper and divide your dough into 8 equal portions. Form the dough into small balls and place them on the baking sheet. Cover them with a clean cloth and let them rise again in a warm place for one to two hours.
• Place a shallow baking sheet on the lower rack of your oven and preheat it to 200°C (400°F). Mix the remaining egg with a tablespoon of water and brush the rolls.
• Bake for 15 minutes, rotating your baking sheet halfway through.