Cook pasta according to packet instructions. Drain and add to a large baking dish.
Mix the pasta sauce through the cooked pasta adding enough water to loosen. (Baking in the oven will dry out the pasta a bit so add enough water to make a loose sauce.) Adjust seasoning. Add more chilli flakes if required.
Preheat the oven to 180 C.
Slice the eggplant lengthwise into thin strips. You want about 12 slices in total. Toss with olive oil to coat all the slices evenly. Lay them out on a large baking tray without too many overlaps. Roast for 25-30 mins until nicely browned.
Add spinach leaves to boiling water and cook until just wilted, about 2 mins. Run the spinach under cold water to cool it down completely. Squeeze out all the excess water from the spinach with your hands.
Add the spinach, paneer, green chillies and salt to a blender jar and pulse to get a coarse mixture.
Divide the filling evenly between the eggplant slices. Lay the filling on one side of the eggplant slice and form them into rolls.
Top the pasta with the eggplant rolls. Cover the baking dish with foil and bake for 20 mins. Serve immediately.