Bring the quail eggs to room temperature before cooking. Heat a circulating water bath (or a saucepan filled with water) to 63.5°C (147°F).
Place the eggs on a perforated tray, immerse in the water and cook for 45 minutes. Remove the eggs and leave to cool at room temperature. Peel the eggs, place in a bowl and lightly coat with the olive oil to prevent them sticking together. Keep warm