Egg Salad with Capers and Spinach on Toasted Brioche

Name: Egg Salad with Capers and Spinach on Toasted Brioche
Ingredients: 16 large eggs; 2 medium shallots, 1 minced,1 thinly sliced; 1 tablespoon Champagne vinegar or white wine vinegar; 2/3 cup mayonnaise; 3 tablespoons whole-grain mustard; 1 large celery rib, finely chopped; 2 1/2 tablespoons drained capers, patted dry and finely chopped; 2 tablespoons minced chives; 1 teaspoon fresh lemon juice; Salt and freshly ground pepper; 1 tablespoon extra-virgin olive oil; Two 10-ounce bags of washed curly spinach, tough stems discarded; 20 slices of brioche cut from a rectangular loaf, lightly toasted