Place parsley into TM bowl and chop 3 sec/speed 6. Remove from bowl and set aside.
Place cheese into TM bowl and mill 3 sec/speed 7. Remove from bowl and set aside.
Place sweet potatoes into simmering basket, insert into TM bowl and pour 1 Litre water over. Place spinach into steamer dish and set into position. Cook 20 min/Varoma/speed 4. Remove steamer, set aside.
Remove and drain sweet potatoes, return them to TM bowl and add butter, seasoning and milk. Mash 10 sec/speed 6. Set aside.
Place onion and EVOO into clean, dry TM bowl and chop 4 sec/speed 4. Add carrot and saute 4 min/Varoma/speed 1.
Add mascarpone, lemon juice, mustard, nutmeg, and combine 5 sec/Reverse/speed soft. Fold in tuna and peas with a spatula.
Preheat oven to 200ºC. Butter a 20cm deep pie dish. Pour tuna mixture into dish, top with wilted spinach, finish with mashed potato and sprinkle with parsley and cheese. Bake for 20 minutes until well browned. Serve hot.