Cook pasta in large saucepan of lightly salted boiling water until al dente, following packet instructions. Add broccoli and cauliflower for the last 3 minutes of cooking time. Drain pasta and vegetables in a large colander.
Rinse pan and return to a low heat. Add blue cheese. Cook, stirring often, until cheese melts into a smooth sauce.
Add pasta and vegetables; stir gently to coat well and heat through. Season to taste with nutmeg, salt and black pepper.