Mix flour, 2 teaspoons of sugar and salt in one bowl. Activate the yeast in some lukewarm water mixed with 1 tablespoon of sugar. Put lukewarm water, the remaining sugar and olive oil in another bowl.
When the yeast is activated, mix all the ingredients. The longer you knead, the more gluten will develop and the softer and airier the dough will be. Make sure to knead with the lower part of the palm, not with a mixer.
Once you have kneaded the dough, let it rise for one hour. The longer you let it rise, the airier it will be. After it has risen, form the dough into the desired shape and leave for another 15 minutes.
Place the dough in the oven for steaming at 95°C for 2 minutes (100% humidity). If you do not have such an oven, then put a pot of boiling water and a Chinese cooking basket on the bottom of the oven. Leave to steam for 4 minutes.
Mix the ingredients for the tuna cream until you get a smooth cream.
Mix the tapenade ingredients in a separate bowl.
Clean the onions, cut into slices and blanch in boiling water for 2 minutes. Drain, cool and dry well with a kitchen cloth. Mix vegetable oil and lemon juice with a stick blender for about a minute. Place the onions in a bowl and cover with a mixture of oil and lemon. Leave in the refrigerator for a few hours before use.
After the steaming, add tomato passata on the dough and bake it in the oven for 5 to 6 minutes at 225°C. When the pizza is done, add zucchini, tuna cream, tapenade and pickled onions.