I do not usually make a traditional Spanish Omelet, but instead make more of a frittata. However, a Spanish omelet is a good base on which to grow and is tasty, probably due in part to the large amount of fat added to it. A traditional Spanish Omelet only contains thinly sliced potatoes and onions, along with eggs. My frittata-like take usually consists of other ingredients thrown in with a quarter of the olive oil. But I did start with a traditional Spanish Omelet with the only addition being rosemary as I grow it inside and think it pairs well with the potatoes and onions. While I prefer to have some more vegetables in my meals, the Spanish Omelet is a good base. Some additions could be spinach, tomatoes, and feta cheese, or sausage and bell pepper. The possibilities are practically endless and it is a good way to clear out produce from your refrigerator. If I am adding additional ingredients I will usually cut the amount of onions and potatoes in half or more.
Except in certain cases (like breads or making a roux), measurements are estimates. Spices I usually eye then adjust with tasting. Pepper should be freshly ground to get the best flavor.
The following abbreviations are used in the recipes:
C: cup
T: tablespoon
t: teaspoon
lb: pound
oz: ounce
g: gram
fl oz: fluid ounce
in: inch
ft: foot/feet
1T = 3t
1/4C = 8T
8fl oz = 1C