Best Ever Egg Salad Sandwich

Makes 4 sandwiches.
Egg salad sandwiches never sounded, nor tasted, delicious, to me until I tried the one from Il Cane Rosso, the now closed café in SF’s Ferry Building. The sandwich was open-faced, the egg was still warm, the mayo was homemade, and the focaccia was thin and crispy enough to compliment the texture of the salad. I’ve adapted this recipe a bit to speed things up – because the café version is too time-consuming. If you do want to try the fancier version, make a bagna cauda butter and homemade mayo, the recipes for which are below the main recipe. 

8 eggs
1 tablespoon finely chopped shallots or red onion
2 tablespoons vinegar (apple cider, white wine or red wine)
½ cup mayonnaise, preferably Hellman’s (Best Food) brand (for homemade mayo, see below*)
Zest of ½ lemon
1 teaspoon lemon juice
1/8 teaspoon grated garlic
Salt
Freshly ground black pepper
2 tablespoons finely chopped parsley
1 tablespoon finely chopped tarragon
1 tablespoon finely chopped chives (can substitute with more tarragon)
2 tablespoons capers
2 hero loaf breads, halved and toasted (or 4 slices of any bread)
4 tablespoons salted butter, softened (for fancy butter see below*)
4 slices provolone, cheddar or any cheese 

1. Boil the eggs: Fill a large saucepan 2/3 full with water and bring it to a boil. Add the eggs, and boil them for 10 minutes. Using a slotted spoon, transfer the eggs to a
bowl full of ice water. Crack the eggs on a hard surface and return them to the ice water mixture to allow the cold water to seep under the shells. Peel the eggs, then roughly chop them and place them in a large bowl. Set aside.
2. In a small bow, combine the shallots or red onion with the vinegar and set aside to macerate for a few minutes.
3. In another small bowl, mix the mayonnaise, lemon zest and juice, garlic and a pinch each of salt and pepper. Taste and adjust seasoning.
4. Drain the shallots or onions from the vinegar. Add them to the large bowl of eggs, along with the parsley, tarragon, chives, capers, and 1/4 cup of the mayonnaise, and mix until combined. Taste and adjust seasoning with more salt, pepper and mayonnaise as needed.
5. To serve: Set the oven to broil. Toast the bread slices and butter one side of each slice. Place the bread slices on a baking sheet, divide the egg between the four slices, top with cheese and broil until the cheese has melted. Serve with a green salad.

* For a fancier version: add ½ teaspoon minced garlic and ½ teaspoon minced and mashed anchovy to the butter. Swap the mayonnaise for this homemade aioli.