In a jug, mix the yeast, sugar and olive oil into the water and leave for a few minutes, then pour into the well. Using your fingers, bring the flour in gradually from the sides and swirl it into the liquid. Keep mixing, drawing larger amounts of flour in, and when it all starts to come together, work the rest of the flour in with your clean, flour-dusted hands. Knead until you have a sticky, springy dough.