Cook pasta al dente, according to package instructions.
Meanwhile, place oil into a large frying pan over medium-high heat. Add onion and sauté, 5mins.
Add zucchini and garlic, sauté further 5mins.
Add butter, stock, and lemon juice. Cook, 2mins.
Stir in optional parmesan, toss sauce with drained pasta. Season with salt and pepper.
-Everyone loves this sauce – prepare one serve of low protein pasta and three serves of regular pasta if others prefer.
-This sauce stays fresh in an airtight container in the refrigerator for 2-3 days.