Bring a medium stockpot of water to a boil and lower to a simmer. Place eggs carefully in the water and set a timer to 7 minutes. Prep an ice bath near the eggs.
After 7 minutes, remove two of the eggs and place in the ice bath and let the other 3 cook for another 2 minutes (so 9 minutes total).
Peel the cooled eggs and slice in half. Set aside the soft boiled eggs (you removed those first).
Place the other eggs in a medium bowl with mayonnaise and chives. Mash with a fork until well mashed. Season with salt and pepper to taste (remember your lox will add a little more salt.)
Set our your challah slices and top with a slice of lox on each. Then put the soft boiled egg slices yolk side down on the lox. Top with the egg salad, making sure to get between the egg halves.
Top with the other challah slices and cut the long way so you're cutting the soft boiled eggs in half. Serve immediately!