75g(1 cup) not packed light cheddar, coarsley grated
Salt and pepper to season
Preheat oven to 200C / 400F / 180C fan forced.
First two steps below can be done at same time.
Peel and chop potatoes into large chunks. Put them in cold water in saucepan. Bring to the boil and cook for 10 minutes. Drain. Mash and set aside.
Bring another pan of water to the boil. Add 1/2 tablespoon of salt and then the pasta and boil for 10 minutes. Reserve 1/4 cup of the cooking water before draining the rest away. The pasta should not be cooked through.
Heat oil in saucepan over medium heat. Add the onion and garlic and sauté for a couple of minutes until softened.
Add the ham and thyme and sauté for a minute or so until the ham gets a little colour.
Add the spinach and allow it to wilt a little before turning off the heat.
Tip the cooked mixture into the bowl with the mashed sweet potato, then add the ricotta, nutmeg and salt and pepper to taste. Mix thoroughly.
Pour the reserved pasta water into a 6 cup capacity casserole dish (or the same pan you cooked everything in as long as it is oven safe).
Fill each shell with the filling and sit them side by side in the dish.
Sprinkle over the cheese and a little more salt & pepper.
Bake for 25 minutes or until golden on top.
I use a standard Australian 20ml tablespoon (4 teaspoons worldwide)
If you can't find jumbo pasta shells, you can use cannelloni tubes or lasagna sheets to make it in the form of lasagna