In a big bowl, add luke warm water, yeast and sugar. Mix well and allow to stand until the yeast blooms (about 10 minutes).

Add vinegar, salt, egg and oil and whisk well.

Add plain flour and knead until you get a smooth and sticky dough.

Add butter and knead well.

Cover and allow to rise until double in size about (30-40 minutes).

Now deflate the dough and divide into 6 parts.

Roll each part into a ball and place on a baking tray leaving a gap between the dough balls.

Allow to double in size again. This time it will take only 10-15 minutes.

Meanwhile, preheat the oven to 180°C.

When the brioche are double in size, Beat an egg yolk and brush each brioche with it.

Top with nigella seeds.

Bake in the oven at 180°C using upper and lower rod for 20 minutes or until the top is golden brown.

Take out and enjoy with your favorite meal.