In a small bowl, mix the warm water, stir in 1 tsp sugar and 2 teaspoons active yeast. Set aside for about 15 minutes, until the mixture rises slightly and froths.
In a large and deep bowl, add the flour, sea salt, yeast mixture, and olive oil and knead for about 4-5 minutes, until all the olive oil is absorbed and the dough is soft and elastic. Cover with cling film and set aside in a warm environment for about 1 hour, until it rises and almost doubles in volume.
Make the toppings
Preheat the oven to 390°F (200°C). Place your pizza stone in the oven. Leave it in for 30 minutes.
Mix the sliced tomatoes with the onions slices in a bowl. Add three or four tablespoons of oil, sea salt, and freshly ground pepper.
Open the dough with your hands and fingers in a circle of about 14 inches/ 38 cm diameter. Transfer it to a floured pizza peel if you have one; if not, take out the pizza stone very carefully because it will be super hot and assemble ladenia on there.
Add the tomatoes and onions all over the dough, leaving a small border around the pizza.Sprinkle with oregano, coarse salt, and freshly ground pepper. Sprinkle some olive oil on top.
Transfer ladenia from the pizza peel to the pizza stone in the oven. Bake for about 20-30 minutes until the onions are slightly caramelized on the surface, and the dough is browned below.
Alternative oven cooking option on a baking sheet
Brush some olive oil on a large rimmed baking sheet.
Open the dough with your fingers to cover the baking sheet. Create a ½ inch (1.5 cm) thicker border of dough. Drain the liquids and add the tomatoes and onions on top. Spread evenly.
Sprinkle with oregano, coarse salt, and freshly ground pepper. Sprinkle some olive oil all over.
Bake for about 20-30 minutes until the onions are slightly caramelized on the surface and the dough is browned below.
You can check how the crust is browning by carefully lifting one corner.
Nutritional Info – Please keep in mind that the nutritional information provided is only an estimate and can vary based on the products used.