Place the eggs in a small saucepan. Fill the pan with water until the eggs are just shy of being entirely covered. Heat over high until the eggs boil, turn the heat down to medium, and gently simmer the eggs for 12 minutes. Remove the eggs from the stove and immediately drain off the water and get the eggs in a very cold ice bath. This will keep the yolks from having a greenish-gray ring around the edge.

Once the eggs cool, peel and cut them in half. Place the yolks in a small bowl and roughly chop the whites. Smash the yolks really well against the side of the bowl. You're looking for a fine sand-like consistency. Next, mix in the very soft butter and continue to smash/whip the yolks until they are very smooth and creamy. Mix in the mayo, mustard, paprika, and salt and pepper to taste. Combine the yolk mixture with the chopped whites, parsley, and celery. Serve with toasty bread. Even better the next day.