Cauliflower, Tomatoes, and Pepperoni Pasta

Ingredients

• 1 head cauliflower
• 2 tablespoon olive oil
• 2 tablespoon kosher salt
• salt and pepper (to taste)
• 12 ounces medium shells or other short pasta
• 1 pint grape tomatoes
• 6 ounces pepperoni (thinly sliced)
• 1/2 cup Italian flat-leaf parsley (chopped)
• 1 onion (sliced into one inch pieces)