Heat 1 tablespoon extra virgin olive oil in a wide pot over medium heat. Add the onion and zucchini and cook, stirring occasionally, for 5 minutes. Season well with salt and pepper.

Add the scallion whites, chickpeas, and garlic powder. Add another pinch of salt and pepper. Cook over medium-low heat for 20–30 minutes, stirring and occasionally mashing the chickpeas as the zucchini cooks down. If needed, add a few splashes of water if the zucchini begins to stick. Adjust the heat as needed if the zucchini cooks down too quickly.

Add the scallion greens and half the minced parsley to the zucchini and simmer for 5 minutes. Taste and add salt and pepper. Mashing a few chickpeas will create a paste-like consistency in the pot.

Bring a large pot of generously salted water to a boil as the zucchini cooks. Add the pasta and cook according to the package instructions. Scoop out ¾ cup of pasta water and set it aside. Drain the pasta.

Combine the rest of the parsley with the lemon juice, Dijon mustard, and Parmesan cheese. Add 1 tablespoon extra virgin olive oil and whisk until a smooth paste forms. Add a few shakes of black pepper to taste.

Add ¼ cup of the pasta water to the Dijon-Parmesan mixture and whisk until smooth.