Chilli, zucchini and lemon pasta

Ingredients

• 375 gram spaghetti
• 2 tablespoon olive oil
• 1 onion, chopped
• 1 clove garlic, crushed
• 1/2 teaspoon dried chilli flakes
• 2 zucchini, grated
• 1 lemon, finely grated rind and juice
• 1/3 cup chopped parsley
• 1/3 cup shredded parmesan