Prepare

Thoroughly wash the celeriac; a brush (a clean toothbrush) works well for reaching between the roots. Dry and (using clean hands!) rub with butter all over. Place on top of two sheets of aluminum foil that you have stacked crosswise.

Briefly crush the fennel and caraway using a pestle and mortar. Sprinkle the celeriac with salt, pepper, and the ground seeds. Also top with the (unpeeled) loose garlic cloves. Fold the foil over the celeriac so it is is nicely sealed and place on a baking sheet.

Make

Preheat the oven to 350°F (180°C).

Bake the celeriac for about 2 hours, until you can effortlessly puncture it with a sharp knife. For the last 30 minutes, place the halved oranges, clementines, and lemons as well as the halved garlic bulb on the baking sheet alongside the celeriac in the oven.

Open the foil, remove the loose garlic cloves, and roast the celeriac uncovered for another 30 minutes to get a nice brown crust.

In the meantime—this can be easily done after you serve the starter—quickly make the sauce: Warm up the marmalade along with the chopped rosemary and the bay leaves in a saucepan. Squeeze 2 of the roasted orange halves, 2 of the clementine halves, and perhaps 1 lemon half, all of which should be still warm from the oven, over the mixture. (Naturally, keep some of the roasted fruits for garnish.)

Press some roasted garlic gloves and stir these into the sauce. Stir in the mustard and slowly bring the sauce to a boil. Douse with vinegar and a splash of brandy. Season with some salt and pepper.

Place the celeriac on a large (preheated!) dish. Pour the sauce over it. Arrange the rest of the roasted fruits around the celeriac and garnish with a handsome sprig of rosemary, which will now look suspiciously like a pine twig.