Press garlic flat. Mix crème fraîche and mustard, season with salt and pepper. Wash the rabbit parts, dab dry and brush with the mustard mixture. Put the rabbit parts into a greased, ovenproof dish.
Pour on broth and white wine. Add garlic and braise in the preheated oven (electric cooker: 200 °C/ circulating air: 175 °C/ gas: see manufacturer) for 1 1/4 - 1 1/2 hours. Turn the rabbit parts in between.
Wash the rosemary, shake dry and remove the needles. Wash the potatoes thoroughly. Spread the potatoes and rosemary around the rabbit parts about 35 minutes before the end of the cooking time. Drizzle with olive oil, season with salt and pepper.
Wash and clean the spring onions and cut them into thin rings. Remove rabbit from the oven, sprinkle with spring onions and serve immediately.