I generally reach for olive oil when cooking, a natural choice for me in Provence, but its often strong fruity and peppery notes can compete with other flavors, so a mild-flavored vegetable oil (such as sunflower) is often preferable to use for infusing.
Tips
• Always use fresh herbs, not dried ones.
• Clean and dry any herbs you are using to infuse the oil.
• Blanching and refreshing herbs before infusing will help retain their bright color.
• Never use flavored oils for deep-frying—any herb particles will burn at high frying temperatures.
• Oils should be stored in the refrigerator. Fat crystals appear when the oil is stored at a cool temperature, giving it a cloudy appearance that will disappear when the oil comes back to room temperature. Be sure to remove your oils from the refrigerator 15 to 20 minutes before using and return them to the refrigerator promptly once used.