Cut the fennel bulbs in half and discard the stalk. In a frying pan (with an ovenproof handle), sauté the fennel bulbs with olive oil. Add the shallots and garlic. When the whole has taken color, extinguish with the clear soup. Cover the pan with a lid and cook at low temperature for 20 minutes.
Then pour the remaining stock on the cut sides of the tubers and sprinkle them with butter flakes, coarse pepper and salt. Briefly gratinate in the oven.