- 3 tablespoons extra-virgin olive oil, plus more for brushing
- 1 cup (packed) minced yellow onion
- 2 medium garlic cloves, minced
- 1/4 cup finely chopped fresh basil
- 1 tablespoon minced fresh thyme
- 2 teaspoons minced fresh rosemary
- Freshly ground pepper
- 1 1/2 cups lukewarm water (105° to 115°)
- 1 cup lukewarm milk (105° to 115°)
- 1 scant tablespoon table salt
- 2 teaspoons plus a pinch of sugar
- One 1/4-ounce envelope dry yeast
- About 6 1/2 cups bread flour
- Cornmeal, for dusting
- Coarse salt, for sprinkling
- 1/4 cup ice water
- Heat the olive oil in a medium skillet over moderate heat. Stir in the onion and garlic, reduce the heat to low and cook until softened and fragrant, about 3 minutes. Add the herbs and a generous amount of pepper and cook for 1 minute. Transfer the mixture to a large bowl. Stir in 1 cup of the water, then the milk, table salt and 2 teaspoons sugar.
- In a small bowl, dissolve the yeast and the pinch of sugar in the remaining 1/2 cup lukewarm water until creamy and starting to bubble. Add to the onion mixture. Stir in the flour, 1 cup at a time, just until the dough becomes too stiff to stir. Turn out the dough onto a lightly floured work surface. With the help of a dough scraper, knead in only as much additional flour as necessary to keep the dough from sticking. Knead the dough until smooth, supple and elastic, about 5 minutes.
- Generously grease a clean large bowl with olive oil. Transfer the dough to the bowl and turn the bowl to coat with oil. Cover the bowl with plastic wrap and a kitchen towel. If desired, label the bowl to remind you when to punch down and shape the dough. Set aside in a warm draft-free spot until doubled in bulk, about 2 hours.
- Punch down the dough. Re-cover the bowl and let the let the dough rise again until doubled, about 1 hour.
- Brush olive oil over the bottom of a 17-by-13-by-1-inch black steel or heavy aluminum baking sheet. Sprinkle cornmeal on the pan, then tap out excess.
- Punch down the dough and turn it out onto a cornmeal-dusted work surface. Turn the dough over and over to coat lightly with cornmeal and shape into a rough rectangle. Lift the dough and place in the prepared pan. Gently pull, push and pat the dough so it fills the baking sheet. Let the dough rise uncovered in a draft-free spot until billowy, 45 minutes to 1 hour.
- Preheat the oven to 450° and position a rack in the bottom third. If using a baking stone or tiles, place on the rack and heat for 30 minutes.
- Dip your fingers in flour and make many deep indentations in the dough. Brush lightly with olive oil and sprinkle with coarse salt.
- Place the baking sheet in the oven, toss the ice water on the oven floor and bake the focaccia for about 30 minutes, until the edges are crisp and a deep golden color. Using a long metal spatula, slide the focaccia onto a large rack to cool. To serve, cut into pieces with a serrated knife.
Lauren Groveman is the author of The I Love to Cook Book: Rediscovering the Joy of Cooking for Family and Friends.