In a large mixing bowl combine the warm water with the yeast and stir well.
Add the olive oil, salt and flour and use a spatula to mix until everything is combined and a sticky dough forms. Use your hand to knead for just a minute until the dough comes together into a ball.
Drizzle the top of the dough with a little olive oil then cover the bowl with a lid or a kitchen towel. Place in a draft free area (your oven is a great place) and allow to rise for 1.5 to 2 hours until doubled in size.
Lightly oil a 10 inch cast iron skillet then dump the focaccia dough inside.
Use your hand to spread the dough inside the skillet all the way to the sides.
Using the tip of your fingers press all over the top to create dimples.
Lightly drizzle with some olive oil then add your toppings: olives, tomatoes and rosemary or whatever you like to add here.
Finish with a sprinkling of Fleur the Sel (sea salt flakes) and cover with a lid or towel. Allow the dough to rise again at room temperature for another 1 to 2 hours until the dough looks light and fluffy and risen.
Meanwhile preheat your oven to 400”F.
Bake the focaccia bread uncovered for 25 to 35 minutes until the top and the sides are a light golden color. Check at the 25 minute mark, sometimes it's done quicker depending on how many toppings you add as well.
Transfer the pan to a cooling rack and allow to cool off completely before slicing.
Alternatively you can cook the focaccia bread in a 10 inch pan instead of the skillet.