Ingredients

• 1 onion, plus 2 more for caramelizing
• 2 scallions
• Leek greens
• 1 pint neutral oil
• 1 garlic clove, smashed
• Sprig of thyme (optional)
• Sprig of parsley (optional)
• Egg, lemon juice, and salt for the mayo (see step 4)

Instructions

1. Char 1 onion, 2 scallions, and the leek greens.
2. Add the charred alliums to 1 pint of oil along with the smashed garlic clove and, if using, the thyme and parsley. Let steep for 24 hours.
3. Strain the oil.
4. Make mayo using the infused oil, following the Serious Eats two-minute mayonnaise method. Set aside.
5. Caramelize 2 onions and let them cool completely.
6. Mix the caramelized onions into the mayo.
7. Serve with chips or cut vegetables.