Cook pappardelle according to package directions. Reserve 1/2 cup pasta cooking water; drain.
Heat 1 tablespoon of oil in a large skillet over high heat. Add fennel and cook, stirring occasionally, until deep golden-brown and crisp-tender, about 2-4 minutes. Season with salt and pepper, to taste. Transfer to a plate and set aside.
In the same skillet over high heat, add radicchio and cook, stirring frequently, until lightly charred, about 1 minute. Season with salt and pepper, to taste. Transfer to the same plate as the fennel and set aside.
In the same skillet, heat remaining oil and butter over medium heat. Add garlic and cook until fragrant, about 30 seconds. Add Locatelli Pecorino Romano Cheese, heavy cream and 1/4 cup of reserved pasta cooking water. Cook, stirring frequently, until a smooth sauce forms, about 2-3 minutes. Add pasta and cook, stirring constantly, and adding more pasta water as needed, until pasta is coated, about 1-2 minutes. Remove from heat and stir in fennel and radicchio until coated.
Top with fennel fronds, additional Locatelli Pecorino Romano Cheese, crushed red pepper flakes and parsley. Serve immediately.