Step 1

Cook cavatelli; drain, reserving ¾ cup pasta cooking liquid.

Step 2

Meanwhile, heat oil in a large skillet over medium heat. Add leek and red pepper flakes; season with salt and pepper. Cook, stirring often, until soft, about 5 minutes. Add zucchini and cook, stirring occasionally, until soft, about 5 minutes.

Step 3

Toss in pasta and reserved pasta cooking liquid; cook until sauce coats pasta, about 2 minutes. Toss in Pecorino.