1 pound chicory or escarole, coarsely chopped and washed
1 cup chicken stock or low-sodium broth
1/4 cup grated pecorino, plus more for serving
2 tablespoons shredded mint
In a large pot of boiling salted water, cook the pasta until al dente. Drain well.
Meanwhile, in a large, deep skillet, heat 2 tablespoons of the olive oil until shimmering. Add the sausage and cook over moderately high heat, breaking it up with a wooden spoon, until browned, about 7 minutes. Using a slotted spoon, transfer the sausage to a plate.
Add the garlic, crushed red pepper and the remaining 2 tablespoons of olive oil to the skillet and cook until fragrant, about 1 minute. Add the chicory with any water clinging to the leaves and season with salt. Cover and cook until wilted, about 2 minutes. Uncover and cook until the chicory is tender and the liquid has evaporated, about 5 minutes longer.
Add the pasta to the skillet along with the sausage, chicken stock and pecorino and cook over moderate heat, stirring constantly, until the liquid is slightly reduced and creamy, about 3 minutes. Stir in the mint and serve right away, passing extra cheese at the table.