How to Make It
Whisk together olive oil and canola oil in a bowl or glass. Combine eggs, capers, lemon zest, mustard (if using), and garlic in a food processor; process until well combined, about 30 seconds. With processor running, gradually drizzle in oil mixture, blending until thickened and creamy, about 30 seconds. Transfer mixture to a bowl; stir in lemon juice and salt. Store, covered, in refrigerator up to 1 week.