Place the dry dough ingredients (wholegrain flour, white flour, yeast and salt) in a bowl and mix together. Add the wet dough ingredients (olive oil and water) and mix with a spoon to form a rough, wet dough.
Rub a little olive oil on your hands to stop the dough sticking - it will be pretty wet at this stage - and stretch the dough by hand, folding it over itself and rotating the bowl 90 degrees before repeating. Do this for about 3 minutes.
Let the dough rest for ten minutes to relax.
Place the dough on a well oiled surface (about one tablespoon oil) and knead for 3 minutes, adding a little more oil if the dough starts to stick, then place in an oiled bowl and cover. Set aside to rise until 3-4 times its original size (roughly one hour).
Transfer the dough to an oiled glass or ceramic dish (30 x 22cm / 12 x 9"), pressing down and pushing it out flat across the bottom of the dish. Spread the toppings (mixed sliced olives, olive oil and thyme) across the surface. Cover and leave to rise until it has risen to 3 times its height (roughly one hour). Towards the end of this time, about 20 minutes before it's finished, start pre-heating the oven (220 °C, Fan 200 °C, 425 °F, Gas 7) .
Once the dough has risen and the oven is heated, bake the bread on the centre shelf for 40-50 minutes until the top is golden brown. Allow to cool for 10 minutes before drizzling with the tablespoon of oil and serving.