First, make the dough. In a small bowl, combine the yeast, sugar and warm water. Stir lightly and cover with clingfilm. Set aside for 5 to 10 minutes until frothy.
Now in the bowl of a stand mixer or a large mixing bowl, combine the flour, salt and olive oil. Mix on low speed (or use a silicone spatula if doing this by hand), then pour in the yeast mixture.
Let the mixer run on medium-low till the dough begins to come together. Sprinkle on just a little flour if it's sticking too much to the bowl. In 3 to 4 minutes it should clear the sides of the mixer bowl, but still look a little shaggy. If doing this by hand, continue using the spatula to bring the dough together.
Turn the dough out onto a lightly floured surface (even if using a mixer), and knead by hand for another 2 to 3 minutes till smooth and when poked with a finger, the dough should slowly bounce back. Depending on how warm or cold it is your kitchen, this could take more or less time. Sprinkle flour or a few drops of oil to prevent sticking.
Place the dough in a lightly greased bowl and cover with clingfilm. Set aside for 1 hour. The dough won't exactly double, but it will puff up a bit. At this point, wrap the dough in clingfilm and refrigerate overnight. If you prefer to bake the same day, let the dough rest for a little longer, about 1 and a half to 2 hours. However, the overnight rest is recommended for better flavour.
In the meantime, make the pesto. Simply combine all the ingredients in a food processor or blender and blitz till a coarse paste forms. Adjust the seasonings as needed. I would typically add more oil to pesto, but for pizza I prefer to use less so that the base doesn't get greasy. Let the pesto rest in the fridge for the flavours to develop (overnight is also fine).
When ready to bake, set the dough out at room temperature for 15 minutes. Preheat the oven to 220 C.
Divide the dough into two and on two silicone mats or baking paper, press each one out with your fingertips into a roughly 9" circle, but the shape isn't very important here, yay!
Spread a layer of pesto over each flatbread, then top with olives and cheese. Bake for 20 minutes, or until browned, rotating the tray halfway for even cooking. For a deeper colour, increase the temperature to 250 C in the last few minutes. Let the flatbreads rest for a few minutes, then slice and eat hot! Best made and eaten fresh, although you can refrigerate them for a couple of days. Happy baking!