Place cauliflower florets in a large pot over medium-high heat and cover with water. Bring to a low boil then lower heat to medium and cook for another 6-8 minutes, or until fork tender. Using a slotted spoon, transfer cauliflower to a blender.
Add roasted garlic, smoked paprika and nutritional yeast and blend. Add 2-3 tablespoons reserved cooking liquid, and continue to blend until smooth.
Add more water as needed to thin out sauce while blending. Season with salt, black pepper, and cayenne pepper, if desired.
Heat olive oil in a large skillet over medium heat. Add garlic and cook for 30 seconds, or until fragrant. Add asparagus and other vegetables and saute for 3-4 minutes, until tender.
Add zucchini noodles and cook for 1-2 minutes until just softened - do NOT overcook. Add the sauce in the skillet and mix well to coat. Season to taste and sprinkle with parsley and nutritional yeast, if desired. Serve immediately.
*For a non-vegan option, use Parmesan cheese instead.