Preheat the oven to 180C or 356F.
Take a large L31cm x W25cm x H6cm baking dish and spread a little passata on the bottom. This dish doesn’t need much tomato, so you can leave the bottom dry if you prefer.
Place about 1 1/2 tablespoons of mixture into each eggplant side. Place the mixture on one end of the eggplant, and then roll it up into your little involtini. Place each involtini into the tray, seam side down. Repeat until you have filled all the involtini – the quantity should fit nicely in the tray. See notes on what to do with any leftover eggplant.
Top the snug involtini with a very thin layer of passata and a very generous layer of freshly and cheese. If you’re using regular cheddar, use the small side of the grate, because the fine shreds of cheddar melt a lot better and more aesthetically than thick ones.
Place the involtini in the oven for 20-30 minutes, or until the cheese is bubbly and golden. I like to place it under the grill for a few minutes just to finish it off.
Serve warm. Involtini keeps well in the fridge for a few days.