Step 1

Combine water and yeast in a large bowl and whisk until dissolved. Add 3 tablespoons olive oil, 2 teaspoons salt, black pepper, 1/2 teaspoon fennel, and 1 cup flour. Using a wooden spoon, stir vigorously until well incorporated (mixture will be lumpy). Add remaining flour, about 1/2 cup at a time, until a soft, sticky dough is formed (you may not use all the flour). Oil a large bowl and transfer dough to oiled bowl. Cover with plastic wrap and place in refrigerator overnight.

Step 2

The next day, remove dough from refrigerator and allow to come to room temperature in a warm, draft-free place. Meanwhile, line a baking sheet with parchment paper.

Step 3

Slide dough onto baking sheet preserving as many air pockets as possible. Gently pull and stretch dough to the edges of baking sheet. Press fingertips all over dough to form indentations.

Step 4

Brush top of dough with remaining 1 tablespoon of olive oil and sprinkle with remaining fennel, salt and rosemary. Cover loosely with plastic wrap and let rise in a warm, draft-free area until slightly puffed, about 30 minutes.

Step 5

Meanwhile, heat oven to 450°F and arrange rack in middle. Bake focaccia until deep, golden brown about 20 to 30 minutes. Transfer to a rack and cool.