Dissolve the sourdough starter in a little of the total water, add a teaspoon of sugar, then add the sifted flours. Start kneading, gradually adding the rest of the water. Add the olive oil, and finally the salt.

Let the dough rest for 30 minutes. Then stretch and fold the dough. Repeat the folds two more times, every 30 minutes.

After the last set of folds, shape the dough into a ball and place it in an oiled container with a tight-fitting lid.

Let it rise for 1 hour, then refrigerate the dough overnight. (I usually make the dough in the evening to have focaccia ready for lunch.)

In the morning, take the dough out of the fridge and let it come to room temperature for about 2 hours.

After 2 hours, turn the dough out onto a well-oiled baking sheet. Gently stretch it out without deflating the bubbles. If it resists stretching, let it rest and try again.

Cut the yellow cherry tomatoes in half, season with salt, minced garlic, oregano, and olive oil. Arrange them on the focaccia, pressing them in gently so they sink slightly.

Let the dough rise for 1 1/2 to 2 hours. Sprinkle with more oregano and drizzle with a little olive oil. Bake at 480°F (250°C) for about 30 minutes on the lower rack of the oven.