Moussaka with Rice

I have often enjoyed moussaka made in the classic way with potatoes and aubergines/eggplants and topped with Mornay sauce and grated Gruyère or Parmesan cheese. It tastes delicious; but of course it is very rich, because the aubergines/eggplants and potatoes have been fried and the Mornay sauce has been made with lots of butter. This version, with rice, is intended as a light lunch or supper dish. You can make it in elegant individual dishes or in one big casserole for 4. Serve it hot, with