Peel half the orange into thin strips, zest the other half, and squeeze out the juice. Set zest aside.
Heat olive oil in a medium saucepan over low heat for 1 minute.
Add rosemary and oregano sprigs, stir and fry for 3–4 minutes until fragrant. Remove sprigs and save leaves for garnish.
Add garlic, orange peel, olives, fennel, and red pepper flakes. Stir and fry for 5–6 minutes.
Add the orange juice and cook until the sauce is reduced to a glaze-like consistency, 10 to 12 minutes.
Remove the olives from the pan and place them in a serving dish.
Garnish with the finely grated zest, another pinch of fennel, and the roasted leaves and needles from the oregano and rosemary sprigs.
Serve with fresh bread or crackers, or as a topping on a cheese board.
