Preparation Heat olive oil in heavy large skillet over medium heat. Add leeks, onion, shallots, garlic and thyme. Season with salt and pepper. Sauté until vegetables are crisp-tender, about 5 minutes. Transfer to bowl and cool. Add mayonnaise and chives to onion mixture. Season salsa to taste with salt and pepper.
Preparation Heat olive oil in heavy large skillet over medium heat. Add leeks, onion, shallots, garlic and thyme. Season with salt and pepper. Sauté until vegetables are crisp-tender, about 5 minutes. Transfer to bowl and cool. Add mayonnaise and chives to onion mixture. Season salsa to taste with salt and pepper.