Tagliatelle with Radicchio, Red Wine, and Walnuts

Toast the walnuts in a dry skillet over medium heat for 2-3 minutes until fragrant, then transfer to a cutting board and roughly chop.

Remove the outer leaves of the radicchio, cut into halves and quarters, remove the core, then slice the leaves into finger-wide strips and rinse in cold water.

Bring a large pot of generously salted water to a boil for the pasta.