Cook 2 crushed garlic cloves in 2T olive oil until it colours slightly.
Add 2 cans chopped tomatoes, 1T tomato paste, 1/4t salt.
Bring to boil then lower heat & cook gently, uncovered for 25m. Stir occasionally.
Cover 500g potatoes with cold, salted water in saucepan & bring to boil (halve if large). Lower heat and cook until ¾ cooked. Drain & slice.
Cut 1.5kg pumpkin into chunks, sprinkle with salt & steam until ¾ cooked.
Transfer to cake rack for cooling then cut into cubes.
Slice 250g cow mozzarella.
Grease an ovendish, add the potatoes in a layer, season with salt then add half the pumpkin. Season with salt, pepper & nutmeg.
Spoon over 1/3 tomato sauce & some basil leaves if you have them.
Add the mozzarella, then the rest of the pumpkin & season.
Add the remaining sauce & top with 1/2c parmesan.
Bake 30-40m at 190C fanbake until brown on top & bubbling at edges.
Cool 5m & serve with a tangy salad like mesclun or red onion.