Add the eggs to a saucepan and fill it with cold water. Bring water to a boil and once the boiling point is reached, boil for 8 minutes.
Prep the ingredients per the instructions above.
Take the eggs out of the water and run them under cold water to cool them.
Lightly toast the bread.
Peel the eggs, chop and add them to a bowl. Mix in mayo, using more or less as needed for a creamy consistency, and tarragon (add the desired amount to taste), mustard, and season with salt and pepper to taste.
Layer the bread with tomato, egg salad, onion, and spinach.
Cut in half and serve with pickles, chips, and lemonade.