1/2 cup freshly grated Pecorino Romano cheese (2 ounces)
Preheat the oven to 425°. Lightly oil an 8-by-11 1/2-inch or 9-by-13-inch baking dish. In a medium saucepan, bring the chicken stock and 2 cups of water to a boil. Add 1 teaspoon of salt. Gradually whisk in the cornmeal until smooth. Cook over moderate heat, stirring with a wooden spoon, until thickened, about 10 minutes. Pour the polenta into the baking dish and smooth the top; brush with 1 tablespoon of olive oil. Bake for 1 hour and 15 minutes, until the top and bottom are golden and crusty.
Meanwhile, in a large, deep skillet, heat the remaining 3 tablespoons of olive oil until shimmering. Add the pancetta and cook over moderately high heat until golden, 4 to 5 minutes. Add the onion, garlic and crushed red pepper and cook until the onion softens. Add the broccoli rabe and the remaining 1/4 cup of water, season with salt and pepper and toss gently. Cover and cook until softened, 5 minutes. Uncover and cook, stirring occasionally, until the water has evaporated and the broccoli rabe is tender, 2 minutes longer.
Cut the polenta into 6 pieces and transfer to plates. Stir half of the Pecorino into the broccoli rabe and spoon it over the polenta. Sprinkle with the remaining Pecorino and serve.
The unbaked polenta and the cooked broccoli rabe can be refrigerated overnight.
A simple red will blend best with the flavors here. Consider a Montepulciano d'Abruzzo.