Hand-Kneaded Focaccia | America's Test Kitchen

Ingredients

• 1 medium baking potato (about 9 ounces), peeled and quartered
• 1 1/2 teaspoons instant yeast
• 3 1/2 cups unbleached all-purpose flour
• 1 cup water (warm, 105 to 115 degrees)
• 2 tablespoons extra-virgin olive oil , plus more for oiling bowl and pan
• 1 1/4 teaspoons table salt
• 2 tablespoons extra-virgin olive oil
• 2 tablespoons fresh rosemary
• 3/4 teaspoon sea salt (coarse), or 1 1/4 teaspoons kosher salt