Use a vegetable peeler to remove big pieces of zest from the lemon and orange, being careful to avoid as much of the white pith as you can.
Roughly chop the thyme, rosemary and bay leaves so they're in large pieces.
Add the citrus peels, herbs, garlic, chili flakes and olive oil to a medium saucepan, then place it on the stove over medium low heat.
Bring up to a gentle simmer, stirring occasionally, for about 5 minutes, then turn off the heat.
Add the olives and toss with the hot oil. Add the olive brine and juice from the lemon and orange, then mix to combine
Transfer to a bowl, then cover and let marinate for at least an hour and up to 3 days in the refrigerator. Bring to room temperature before serving