In a large bowl, mix flour, instant yeast, and salt.
Pour in the warm water and olive oil. Stir until a sticky dough forms. It’ll look a bit rough, but that’s okay — perfection is overrated.
Cover the bowl with a towel and let it sit at room temp for 1–2 hours, or until it doubles in size.
Grease a 9x13-inch baking pan with olive oil and gently stretch the dough to fit. Let it rest another 20–30 minutes.
Preheat the oven to 425°F (218°C).
Use your fingers to dimple the dough — yes, get in there like it owes you money. Drizzle with olive oil and sprinkle sea salt and rosemary on top.
Bake for 20–25 minutes, or until golden and puffed. Let it cool just enough so you don’t burn your face eating half of it straight from the pan.