Spiralize the zucchini. Wash and trim the ends. Use a spiralizer or julienne peeler to make noodles.
If they’re very long, snip a few strands with kitchen scissors for easier twirling.
Remove excess moisture. Toss the zoodles with a pinch of salt and let them sit in a colander for 10 minutes. Pat dry with paper towels. This keeps the sauce from getting watery.
Warm the pan. In a large skillet, heat olive oil or butter over medium heat.
Add garlic and cook 30–60 seconds until fragrant. Don’t brown it.
Build the lighter sauce. Pour in the broth and bring to a gentle simmer for 2–3 minutes to reduce slightly. Lower the heat.
Whisk in Greek yogurt until smooth.
Add the cheese. Sprinkle in the Parmesan gradually, whisking until melted and creamy. If the sauce looks too thick, add a splash more broth. If too thin, simmer gently for another minute.
Season and brighten. Stir in lemon zest, red pepper flakes if using, and a few grinds of black pepper.
Taste and add salt as needed.
Cook the zoodles briefly. Add the zucchini noodles to the pan and toss gently with tongs for 1–3 minutes. You want them just tender, not soggy. They continue to soften off the heat.
Finish and serve. Stir in parsley and any add-ins like cooked chicken or shrimp.
Plate immediately and top with a little extra Parmesan if you like.