Add the potatoes to a large pot and fill it with cold water until the water covers the potatoes by about 1 inch. Add 1 teaspoon of salt to the water. Bring the pot to a boil. Boil the potatoes for 15 - 20 minutes, until tender when pierced with a fork. Drain and set aside.
While the potatoes cook, in a large bowl stir together: mayonnaise, lemon juice, dijon mustard, garlic powder, 1 teaspoon salt and pepper.
Once the potatoes have cooled, cut them into roughly ½ inch pieces. Add the potatoes to the bowl with the mayonnaise along with the eggs, celery, and green onions. Stir gently to mix.
Serve cold, optionally topped with a sprinkle of paprika or chopped chives.
