Peel the parsnips and cut off the tips. Finely dice the thin part. Cut the thicker end into slices about 3 cm thick and hollow out. Blanch the rings for 5 minutes. Drain well and place next to each other in a flat, greased casserole dish.
Stew the onion, garlic, parsley and diced parsnips in butter. Add the remaining ingredients and season well with salt and pepper. Fill the parsnip rings with the mixture or stack the filling like a tower. Place small butter stains on top and bake at 200 ° C for about 30 minutes.