Tomato Basil Egg Salad Sandwich

Name: Tomato Basil Egg Salad Sandwich
Ingredients: 8 hard-boiled eggs, sliced; 1/4 cup mayonnaise; 1/2 teaspoon Dijon mustard; 1/4 teaspoon onion powder; 1/8 teaspoon salt; ground black pepper to taste; 10 leaves basil, thinly sliced; 1 tomato, sliced; 4 leaves lettuce; 4 English muffins, split and toasted