Trim Brussel sprouts and remove outer leaves. Cut small ones in half and large ones into quarters. Boil sprouts until almost fork tender about 3 - 5 minutes. Drain well and divide between 6 gratin dishes.
Place ricotta in a medium bowl. Slowly whisk in cream, Dijon, thyme, salt, nutmeg and pepper. In a seperate bowl mix bread crumbs and butter, then mix in parmigiano.
Pour ricotta mixture over Brussel sprouts and sprinkle with bread crumb mixture. Cover with foil, place on a baking sheet and bake for 15 minutes.
Uncover and broil for 2 more minutes until bread crumbs are lightly golden. Serve warm.
OR
Place all Brussel sprouts in a casserole dish, cover with ricotta mixture, top with bread crumbs and bake for approximately 20 minutes covered, remove cover and bake another 5 - 10 minutes until topping is lightly browned.
Notes
Great as either one side casserole dish or individual ones.