Deborah Madison's Cauliflower with Saffron, Pepper Flakes, Plenty of Parsley, and Pasta

Ingredients (10)

• 1 cauliflower (about 1 1/2 pounds), broken into small florets, the core diced
• 2 tablespoons olive oil, plus more for tossing the pasta
• 1 onion, finely diced
• 2 pinches of saffron threads
• 1 large clove garlic, minced
• Scant 1 teaspoon red pepper flakes
• 4 tablespoons finely chopped parsley
• Sea salt
• 8 ounces pasta shells, snails or other shapes
• Grated aged cheese or crumbled feta cheese (optional)