Mix the flour, semolina, yeast and salt.
Mix the water with Olive oil.
Make a well in the center of dry ingredients, gradually add in the water and oil mixture and start mixing it slowly with your hand.
Once it forms a rough shape, take the dough out onto a lightly floured surface and knead for about 10 minutes until smooth, elastic and springy to touch.
Place the dough in a large floured mixing bowl and leave to rise in a warm place for 60-90 minutes until double.
Preheat the oven to 200 Degrees C.
Grease a baking tray (8.5 inch x 8.5 inch) with oil and sprinkle some salt.
Place the dough in a oiled baking tray. Rub some oil in your fingers and prod out the dough to the edges of the tray.
Press the tomatoes and onion into the dough.
Sprinkle with salt and drizzle olive oil on the top.Bake it in a preheated oven for 30 minutes until golden and cooked through.
Remove from the oven, let it cool for 5-10 minutes.
Flip, cut and serve.