Place the flours and ½ tablespoon of sea salt into a large bowl, and make a well in the middle. Add the yeast and sugar to the lukewarm water, and mix with a fork. Leave this for a few minutes and, when it starts to foam, slowly pour it into the well, mixing with a fork as you go. As soon as all the ingredients come together, which may take a minute or so, knead vigorously for around 5 minutes until you have a smooth, springy, soft dough. Lightly oil a large bowl with some olive oil and transfer the dough to the bowl. Dust with a little extra flour, cover with a tea towel and leave to prove in a warm place for 30 minutes until doubled in size. While the dough is rising, preheat your oven to 220°C/425°F/gas 7 and prepare the toppings. For the balsamic onion topping, finely slice the onions and pick the thyme leaves. Fry the onions and thyme in 2 tablespoons of olive oil over a low heat for about 5 minutes. Add 6 tablespoons of balsamic vinegar, reduce for a minute or two, then leave to cool. For the basil and cherry tomato topping, pick and roughly chop the basil leaves and halve the tomatoes. Pop the basil and tomatoes into a bowl and season with sea salt and black pepper, a drizzle of extra virgin olive oil and a tiny splash of white wine vinegar. Peel and slice the garlic and mix into the bowl. To cook the focaccia, as soon as the dough has risen, pound it, then place on a baking tray and spread it out to cover the tray. Push down roughly on top of the dough like a piano to make lots of rough dips and wells. Divide the onion and the tomato toppings over two thirds of the focaccia. For the three-cheese and rosemary topping, break up the Taleggio and the goat’s cheese over the remaining third of the focaccia. Grate a handful of Parmesan cheese and pick the rosemary leaves. Sprinkle both over the final third and season with pepper. Finish with a good drizzle of extra virgin olive oil and a sprinkle of sea salt. Leave to prove for a further 20 minutes, then bake for 20 minutes, until golden on top and soft in the middle.