I want to briefly discuss two aspects of quantities of ingredients for the salads and frittatas. First, quantities and changes when making the recipes for one and second, extending the recipes for multiple servings.
It’s pretty obvious that the main elements in a salad can be decreased or increased as desired without causing any problems. The salads you see in the pictures are generous. For meat or seafood, I am usually including a 5- or 6-ounce portion. I am making these salads for my main meal of the day. I don’t have anything else to eat with the salad, such as bread, and I almost never have dessert. For a lighter lunch, if you have a smaller appetite, or are having other things along with the salad, you may well want to make them smaller.
For the vinaigrette or other dressing, however, the quantities will directly affect the taste. Doubling the amount of some seasoning, for example, will have a significant impact. This is not to say you should not make changes, only to state the obvious that you should be doing so with a desire to change the dressing.
I can’t think of anything that would be easier to scale up to serve more people. You might need to make a little less dressing, because with larger quantities, proportionately less is lost remaining on the sides of the bowl, the whisk, and the spoon. Multiplying the 3 tablespoons of oil and 1 tablespoon of vinegar for the vinaigrette to serve 4 would give 3/4 cup of oil and 1/4 cup for vinegar, making a full cup of dressing. This might be a little much. But why not start with this amount? You can always save any extra and use it on side salads over the next few days.
Frittatas present a different situation where quantities are definitely more important. I like to have my frittatas with generous amounts of the various ingredients mixed into the eggs, and my recipes reflect this. You can always adjust the amounts down, of course. But there’s not much room for increasing the quantities, because there’s only so much that can “fit” in with the eggs and still make it work as a frittata. Of course if you decrease the quantity of one thing, you could have some room for increasing the quantity of another.
Scaling up frittata recipes to serve more people gets a little more complex. The 3-egg frittata is actually a lot for one person, but just about the least you can do with the small pan. Doing a frittata for two, a 4-egg frittata will probably be sufficient. Increasing all of the other ingredients by a third and cooking in the 8-inch omelette pan will certainly work. The frittata will be a little thicker, but it would be very reasonable for a frittata. Serve this with a nice side salad and some fruit and it will make a nice meal.
The next step up requires moving to a larger skillet, typically the standard size 10-inch omelette pan. This doesn’t seem like that big a jump. But the flat portion of the 8-inch pan is actually about 6–1/2 inches across, while it would be closer to 8–1/2 inches for the larger pan. And since the area increases with the square of the radius (sorry, that’s the nerd in me coming out), the flat portion of the 10-inch pan will be around 1–3/4 the area of the smaller pan. That’s close enough to twice the size to make an 8-egg frittata for four very workable in the larger pan, increasing the other ingredients by 2–2/3. And lo and behold, I have seen numbers of recipes calling for frittatas to be made in a 10-inch pan using 8 eggs. Since this is doubling the 4-egg expansion suggested for 2 persons, this frittata should do nicely for 4 servings.
To serve more people, you’ll be cooking the entire frittata in a larger pan in the oven (unless you can use multiple skillets). The various frittata sizes mentioned above have 7 to 11 square inches of surface area per egg (actually a little more when you figure the sides of the pan slope out from the flat bottom). I just looked at a recipe for a frittata using a standard 9 by 13 inch baking pan that used a dozen eggs. That’s 9.75 square inches per egg, right in the middle of my range. So you can use these figures for estimating the sizes of the frittatas you can make in the various baking pans you have available for the number of servings you wish to make.