Mix the marinade ingredients together and coat the ribs thoroughly.
Marinate the covered ribs in the fridge for 12 hours or overnight.
Preheat the oven to 180°C.
Melt butter in a large saucepan and gently fry the garlic and onion for three minutes.
Add the potato, celeriac, and cream to the pan.
Season with nutmeg, salt, and pepper then bring the mixture to a boil.
Transfer the mixture to a shallow gratin dish and place it inside a roasting tray.
Add hot water to the tray until it reaches halfway up the gratin dish sides.
Bake for 30-40 minutes until the top is golden-brown.
Set aside and reheat in a warm oven for 15 minutes before serving.
Place ribs in a roasting tray and roast at 180°C for 40 minutes while basting with reserved marinade.
Reduce the oven temperature to 150°C and roast for another 45 minutes while basting.
Serve the ribs with the dauphinoise and a fresh tomato and green leaf salad.