Make the mayonnaise: Whisk the egg yolks, lemon juice and1 teaspoon salt in a bowl until frothy. Slowly drizzle in the vegetable oil, whisking constantly until completely emulsified.

Make the potato salad: Cook the bacon in a skillet until crisp. Transfer to a paper towel-lined plate to cool, then chop into small bits.

Slice the potatoes 1/4 inch thick; transfer to a pot, cover with water and lightly season with salt. Bring to a simmer over medium heat and cook until just fork tender, 8 to 10 minutes. Drain well.

Combine the bacon, capers, vinegar and chives in a large bowl. Add 1/4 cup mayonnaise (reserve the rest for another use). Gently fold in the warm potatoes and season with salt and pepper.