Step 1

Add the olive oil to a medium pot over medium heat. When warm, add the celery, carrot, and onion. Stir to coat and cook for 2 minutes, or until just starting to soften.

Step 2

Add the broth and raise the heat to high. When the broth starts to boil, turn down the heat to medium so it simmers.

Step 3

Add the pasta. Cook for about 8 minutes, stirring occasionally.

Step 4

Stir in the peas, Parmesan, and lemon zest, if using.

Step 5

Season to taste with salt and pepper. Serve warm.