Penne with Caramelized Radicchio & Balsamic Vinegar | Quick Autumn Pasta

Bring a large pot of plenty of water to a boil and salt generously. Toast the walnut kernels in a non-stick pan without fat over medium heat for 2 to 3 minutes until fragrant, then remove and roughly chop.

Wash the radicchio, pat dry, halve, cut out the core, and cut the leaves into bite-sized strips. Peel and finely dice the red onion and garlic cloves.

Cook the penne pasta in the boiling salted water according to package instructions until al dente. Before draining, ladle out about 100 ml of starchy pasta water and set aside.