In a large bowl, combine the flour, salt, and instant yeast.
Add the warm water and olive oil and stir until a shaggy dough forms.
Turn the dough out onto a lightly floured surface and knead for about 5 minutes until smooth and elastic.
Place the dough in a lightly greased bowl, cover, and let rise for 1 hour.
Preheat your oven to 450°F (230°C).
Punch down the dough to release any air bubbles.
Press the dough into a 12-inch cast iron skillet, making sure to push it up the sides.
Spread the marinara sauce evenly over the dough, leaving a ½-inch border.
Sprinkle the mozzarella cheese over the top.
Bake for 15-20 minutes, or until the crust is golden brown and the cheese is melted and bubbly.
Let the pizza cool for 5 minutes before slicing and serving.
