Start by preparing the yeast. In a cup, dissolve the yeast and the sugar in 1/2 cup of warm water. Let it rest for about 5 minutes until you prepare the rest of the ingredients.
In a large bowl, mix the flour, the salt and the spirulina. Create a small hole in the middle and add the olive oil, the dissolved yeast and the Greek yogurt. Then gradually add more warm water and mix with a spoon until the dough is cohesive. Start using your hands and knead for a few minutes. The dough should be a bit sticky, but should not feel "wet".
Wash your hands and coat them with olive oil. Also grease second bowl with some more olive oil. Lift the dough from the first bowl and shape it. Gently smoothen up the dough from the top to bottom to form a nice ball. Transfer it into the second bowl, and let it rise for 1 hour, covered by a wet towel.
After an hour, preheat the oven at 375°F and line a baking sheet with parchment paper. Coat your hands with some olive oil again so that the dough does not stick to your fingers. I do it most of the time when working with whole wheat flour because the dough should always remain a bit sticky. If you decide to add more flour instead, the bread will become dry and fall apart after cooling down.
Punch down the dough to remove the air trapped. Using your hands, form 6 balls as round as you can but do not over manipulate the dough or it won’t rise properly! Transfer them on the baking sheet.
Optional: In a small bowl, beat an egg with a fork. Using a brush, gently apply the egg wash on the buns and sprinkle some sesame seeds.
Bake for 25 minutes or until a soft crust is formed.
Allow to cool down before cutting and enjoy!