Step 1

Preheat oven to 375 F.

Step 2

Toss potatoes with 1 tablespoon olive oil and 1 teaspoon salt in a large bowl. Arrange potatoes in one layer on a baking tray. Bake until edges begin to turn golden brown, 15 to 20 minutes. Remove from oven and let cool. Increase oven temperature to 475 F.

Step 3

Bring a large pot of salted water to boil. Add broccoli rabe and blanch 30 seconds; drain. Plunge broccoli rabe into a bowl of ice water. Cool and drain again. Lay in one layer on a kitchen towel to thoroughly dry. Cut in 2" pieces.

Step 4

Heat one tablespoon olive oil in skillet over medium heat. Add minced garlic and red pepper flakes. Sauté briefly, 30 seconds. Add broccoli rabe and 1/2 teaspoon salt. Sauté one minute. Remove from heat. Taste and add more salt if necessary.

Step 5

Assemble pizzas: Lightly brush pizza crusts with olive oil. Rub all over with smashed garlic cloves.

Step 6

Arrange one layer mozzarella cheese over crusts. Top with one layer of potatoes and broccoli rabe. Sprinkle one tablespoon rosemary over each crust. Top with grated Pecorino cheese.

Step 7

Bake on pizza stone or on tray on lowest rack in oven until crust is golden brown and cheese is bubbly, about 15 minutes.

Step 8

Before serving, sprinkle with freshly ground black pepper. Garnish with fresh rosemary leaves and drizzle with extra-virgin olive oil.

Step 9

Stir yeast and lukewarm water together in a bowl. Add 1/4 cup all-purpose flour and semolina. Mix well. Let sit until bubbly, about 30 minutes.

Step 10

Combine remaining flour and salt in another bowl. Add to yeast with cold water and olive oil. Mix well to form a dough.

Step 11

Turn dough out onto a lightly floured board and knead with hands until dough is smooth and elastic, about 10 minutes. Or use a mixer with a dough hook, and knead about 5 minutes.

Step 12

Place dough in a lightly oiled bowl and turn to coat all sides with oil. Cover bowl loosely with plastic wrap. Let rise in a warm place until doubled in size, 1 to 2 hours. Punch dough down, and let rise another 45 minutes.

Step 13

Divide dough into 2 equal disks (or 4 if you would like small pizzas.) Let rest 30 minutes before shaping. Lightly flour a work surface. Using your fingers or heels of your hands, stretch the disks out to 10" shapes.