Preheat oven to 375F / 180C.

Remove the base and stalks from the fennel and cut the bulb in half and then into 1/-4-inch slices, lengthwise.

Whisk together the olive oil, mustard, orange juice, honey or petimezi, balsamic, salt and pepper. Toss the fennel in this mixture and place in an oven-proof glass or ceramic roasting dish.

Place the orange slices in between the fennel slices and roast for about 35 minutes, until the fennel is soft and lightly golden. Toss in the dill or fennel fronds and olives and bake another five minutes. Sprinkle the feta over the fennel and turn the oven off. Leave the dish in the oven for 5 minutes. Remove and serve.