Pulled beef cottage pie with cauliflower mash

Ingredients

• oil spray
• 1 large onion, finely diced
• 1 large carrot, grated
• 1 celery stalk, finely sliced or diced
• 2 tsp finely chopped rosemary
• 350g pulled beef
• 1 (250ml) cup pulled beef sauce or 1 cup beef stock
• ¼ (63ml) cup water
• 2 medium potatoes (about 350g unpeeled), peeled and diced
• 2 cups cauliflower florets (150-200g)
• 1 tbsp light butter
• ¼ cup low fat milk
• 4 tsp finely grated parmesan cheese