Cut 4 long thin slices out of the middle of both eggplants, dip in the flour and fry in hot oil on both sides to soften - then drain well on kitchen paper.
Mix together all other ingredients (except the sauces) and season to taste with salt and pepper.
Divide mixture evenly between slices of eggplant and roll eggplant around it - securing with a toothpick.
Place on a shallow baking dish and coat with white sauce, then with the Napoletana sauce.
Cover with foil and bake at 375F or 190C for 30 minutes.
Remove foil for the last 5 minutes.
Serve hot with feta and salad.