Heat onions in olive oil and cook until translucent.
Add cauliflower and cook for 15-20 minutes, or until the cauliflower is close to being tender.
Add the broccoli and garlic and cook for an additional 15 minutes, or until broccoli is nearly tender.
Add the spinach, peas, sweet corn, and uncooked spinach.
Cook for a few minutes until spinach is wilted.
Cook pasta is boiling salted water until pasta is cooked and drain.
Combine pasta with the hot vegetables and add the grated parmesan cheese. Toss to combine. Serve hot, garnished with the freshly sliced basil.