Put both flourtypes and 1/2 tbsp of seasalt in a large bowl and make a hole in the middle. Mix the yeast and sugar with a fork with 300 ml of lukewarm water. Leave for about 2-3 minutes and once it begins to foam a little, pour slowly into the hole while mixing with a fork.
As soon as the ingredients are mixed, knead the dough for about 5 minutes untill you have a smooth and bouncy dough. Grease a large bowl with some oliveoil and put the dough in the middle. Dust with a little flour, cover with a teatowel and leave for about 30 minutes in a warm spot to rise and double in volume. In the meantime heat the oven to 220 C and make the toppings.
For the balsamico dressing, fry the onions and the thyme on a medium to low heat for about 5 minutes in the olive oil. Add the balsamic vinegar and leave it to thicken for about 2 minutes and leave to cool.
For the basil-tomatoetopping; chop the basil coarsely and add in a bowl with the cherry tomatoes. Season with salt, pepper, a little bit of whitewine vinegar and some extra virgin olive oil. Add the garlic and mix everything together.
Beat the dough back once it has risen and put it on a baking tray and press it on the tray until it is fully covered. Press into the top of the dough so you get little holes and dents.
Divide the onion- and the cherry tomato topping over 2/3 of the bread. For the three cheese topping break the taleggio and goatcheese over the uncovered part of the bread. Sprinkle the parmezan and rosemary over the top and add pepper. Sprinkle some oliveoil over the entire bread and add a little seasalt. Leave to rise for another 20 minutes and then put in the oven for 20 minutes untill the top is goldenbrown and the inside is soft.