Makes 1 1/4 cups
In a food processor or blender, blend egg, lemon juice, and sambal oelek for 10 seconds. With the processor running, slowly pour in oil through the feed tube in a slow and steady stream until thoroughly incorporated and mixture is emulsified. Add salt and pepper and pulse once or twice to blend.
Transfer to an airtight container and refrigerate for at least 30 minutes before using. Best if used within 24 hours.