How to Make It
Bring a large pot of salted water to a boil. Meanwhile, in a large deep skillet, toast the walnuts over high heat, stirring constantly, until fragrant, about 5 minutes. Transfer to a plate to cool.
Add 1 teaspoon of the walnut oil to the skillet along with the beans and cook over high heat, stirring, until tender and blackened in spots, about 8 minutes. Add 1 tablespoon of the walnut oil, the shallots, garlic and summer savory and cook until fragrant, about 2 minutes. Add the lemon juice and season with salt and pepper.
Cook the penne in the boiling water until al dente. Drain the pasta, reserving 1 cup of the cooking water. Add the pasta to the skillet and toss with the green beans; stir in some cooking water if the pasta seems dry. Add the ricotta salata, toasted walnuts and the remaining 2 teaspoons of walnut oil; toss well and serve.