Heart-shaped croutons adorn this classic salad. Any leftover dressing can be served on the side or stored in the refrigerator for up to a week.
For the dressing: Place egg yolk, mustard, garlic, anchovies, lemon juice, salt, and pepper in the bowl of a food processor; process until smooth. With processor running, slowly add the olive oil until mixture is smooth and thick. Add 1/4 cup Parmesan; pulse to combine;set aside.
Heat oven to 350 degrees. Make the croutons: Using a 2-inch cookie cutter, cut out heart shapes from the bread slices. Brush each heart with olive oil, and sprinkle with salt and pepper. Place on a baking sheet, and bake until golden brown, 15 to 20 minutes. Remove from oven, and set aside.
Cut lettuce crosswise in 1-inch slices. Place in a salad bowl. Add enough dressing to moisten; toss to combine. Add remaining 3/4 cup Parmesan and reserved croutons; toss again. Serve.