In a large bowl, whisk together the flour, instant yeast, and fine salt.
Add the warm water and olive oil, then stir until a shaggy dough forms and no dry flour remains.
Mix in the chopped sun-dried tomatoes, then cover the bowl and let the dough rise in a warm place until doubled in size, about 1 to 1 1/2 hours.
Generously oil a 9x13-inch baking pan. Transfer the dough to the pan and gently stretch it toward the edges. If it resists, let it rest for 10 minutes, then stretch again.
Cover and let rise again for 20 to 30 minutes, until puffy.
Preheat the oven to 425°F (220°C). Drizzle the dough with more olive oil, dimple the surface with your fingertips, and sprinkle with rosemary and flaky sea salt.
Bake for 22 to 25 minutes, until deeply golden brown.
Cool slightly before slicing and serving warm.