Gather the ingredients - * Flour * Instant yeast * Salt * Water * Olive oil * Rosemary
– In a medium bowl, mix together yeast, salt, and flour. – Add the water to the flour mixture. Mix until a shaggy dough forms with a rubber spatula.
Turn the dough out onto a well-floured surface. Knead for 5-10 minutes until smooth. The dough will be smooth on the outside and feel soft when you press it.
Place the dough in a well-oiled bowl and cover with damp kitchen towel. Rest until doubled in size (about 1-2 hours).
Pour the olive oil into a 12 inch cast iron skillet or a 9x13" pan. Place the dough in the pan and coat in olive oil. Stretch the dough to fit the pan. Cover the pan with a damp kitchen towel and rest until the dough has puffed up and filled the pan (about 1-2 hours). Preheat the oven to 450 degrees F when you have about a half hour left of your rise.
When the dough is ready, lift up the sides to release any air bubbles from underneath the dough. Press your fingers deep into the top of the dough to make the pockets that give focaccia its classic bumps.
Sprinkle the dough with salt and rosemary.
Place the pan on the middle rack of the preheated oven. Bake for 20-25 minutes. The top should be deep golden brown and crispy. Remove from the oven and enjoy warm.