Toasted, seasoned and chopped walnuts take the place of bread crumbs for a crunchy topping in this simple, weeknight-friendly spaghetti meal. A fresh bag of walnuts is ideal in avoiding any rancidness. A plethora of kale, cooked down in a garlicky chile-infused olive oil, makes sure every bite is packed with hearty and lively greens. You don’t need to blanch the kale in advance. Using the starchy pasta water helps the leaves wilt in the same time that the spaghetti cooks, and saves you an extra pot. Finish off the dish with a generous sprinkling of salty pecorino cheese, which holds up well to the heartiness of the kale and walnuts, or use Parmesan.