The number of people served varies, but a guess is 4: It has 4 pieces of bread, about 80 C (calories) per person. The 1 cup of cheese would be 1/4 C per person, and 1/4 cup of that cheese is enough to be noticed. The 3 heads of Romaine is 3/4 a head per person, and that's plenty for a salad. Could add up to ~300 calories, which is a lot for just part of a meal, just a salad, and not a full meal or even a main dish. So, might follow it with something with a lot of protein, a grilled T-bone steak, grilled/roasted chicken, etc.

But, the dressing yields about 3 cups with 2 cups of oil (plus the oil with the anchovies). The 2 cups is 32 tablespoons at 125 calories per tablespoon, ..., might feed 32 people. In that case, leave the dressing as is and increase the lettuce, bread, and cheese.