Mix together bubbly sourdough starter along with water and whole wheat flour to make a sticky dough.
Cover and set aside for two hours.
Remove it from fridge and set it on counter for four hours.
To the same bowl, add in oil, salt, water and flour.
Mix to form a sticky dough.
Cover and set aside for 30 minutes.
Now take it to counter and using a dough scraper, lift it, slap it and fold it. Keep on repeating this for 20 times or until you feel the dough is smooth.
Oil a 7" square tin and place the dough in it. Add more oil on top and press the dough to fill the base of the tin.
Cover with cling film and set aside until double in volume. It may take two hours to four hours depending upon the temperature of your room.
Preheat oven to 250°C.
Use your fingertips to make indentations on top of the dough.
Add generous olive oil or melted butter in the indentations and sprinkle grated garlic, finely chopped onion and dried basil.
Apply milk wash on top of the bread and bake in preheated oven for 25 minutes.
Once the bread is warm enough, slice it up into squares and serve.