How to Make It
In the order recommended by your bread machine manufacturer, combine the yeast, flour, sugar, salt and lukewarm water in the container of your machine. Set the machine on the dough cycle and, if you have the capability, the French bread or white bread mode. Close the cover and let the machine do its thing.
When the dough is ready and the machine signals the end of the cycle, transfer the dough to a lightly floured surface and divide it in half. Shape each half into a rounded disk and transfer the disks to 1 large or 2 small baking sheets. Cover with plastic wrap and set aside to rise until doubled in bulk, usually 45 minutes to 1 hour. (Don't worry if it takes as long as 2 hours.)
Punch down the disks and spread out each one into an 8- to 9-inch round about 1/2 inch thick. Use your knuckles to dimple the top of the dough. Cover and set aside until risen and puffy, about 45 minutes; again, up to 2 hours is fine.
Preheat the oven to 425°. Just before baking, use your knuckles to dimple the surface of each focaccia again. Drizzle the oil over the rounds and spread it into the dimples with the back of a spoon. Sprinkle the focaccia with the kosher salt, and scatter the rosemary leaves on top.
Bake the focaccia in the top third of the oven for about 18 minutes, or until the tops are golden and the bottoms are lightly browned and crisp. Transfer to a wire rack. Cut into wedges and serve at once, or let cool and wrap for later.