Step 1

Make the aïoli: Drape a kitchen towel over a small saucepan. In a medium glass bowl, place the egg yolks and set over the small saucepan so that the bowl stays in place. Using a large whisk, beat the egg yolks, water, salt and garlic until well combined. Whisking constantly, gradually drizzle in the olive oil, drop by drop, until the sauce begins to emulsify and has thickened. Continue adding the olive oil in a steady stream, whisking constantly, until all the olive oil is incorporated. Make ahead: The aïoli can be made a day ahead. Cover and chill. Bring to room temperature before using.

Step 2

Make the aïoli mashed potatoes: Place the potatoes and bay leaves in a large pot and cover with 2 inches of cold water. Season the water generously with salt and bring to a boil. Reduce heat to a simmer and cook until the potatoes are very tender, 18 to 20 minutes. Drain, reserving ½ cup of the cooking liquid, and let the potatoes stand until dry.

Step 3

Place the potatoes back into the pot. Using a wooden spoon, smash the potatoes against the side of the pot. Add the reserved cooking liquid and olive oil and continue smashing and stirring vigorously until combined. Place the pot over medium heat, stirring until the potatoes have warmed through, 2 to 3 minutes. Remove the potatoes from the heat and stir in half the aïoli. The potatoes should look very creamy. Make ahead: Potatoes can be made ahead 5 hours in advance and reheated before stirring in the aïoli.

Step 4

Transfer the potatoes to a serving dish and drizzle with remaining aïoli. Garnish with chives and piment d'Espelette or crushed red pepper flakes. Serve warm. Note: When you're making the aïoli, use a buttery pale-golden olive oil rather than one with a peppery finish, which can be overpowering. Taste as you go, as the aïoli should be creamy, not too garlicky and well-seasoned.