Using a spiralizer, spiralize the zucchini and squash into noodles.
Heat a large nonstick skillet over medium heat. When hot add the olive oil, onions and garlic and cook until fragrant, about 1 to 2 minutes.
Add the zucchini noodles to the onion and garlic mixture and sauté for 1-2 minutes. Season with salt, pepper and red pepper flakes. Toss to combine.
Dust the top of the noodles with parmesan cheese and fresh mint leaves serve. Toss with a tiny bit of the lemon vinaigrette and serve. Save remaining lemon vinaigrette for another salad.