I don't pretend to make authentic Spanish tortillas or Italian frittatas, but they are very much easier than traditional French omelettes. Quite apart from anything else, you can keep them waiting, and even eat them cold if you would like (if you get it right - and I find mine tend to fall apart - you can take them on picnics).
The idea of these omelettes is that they are stuffed full of vegetables. They have way more vegetables than eggs. Spanish ones must contain potatoes and onions, but may also contain things like peppers, chorizo (okay, that's not a vegetable, but hey?), tomatoes.... whatever. Italian ones just contain vegetables. It's probably not a good idea to use too many vegetables that render a great deal of juice when cooked, although one or two. But choose a selection of vegetables that you like: onions, peas, peppers, mushrooms, tomatoes (cherry tomatoes work well), chunks of butternut squash, maybe chopped aubergine or courgette, maybe chunks of carrot or parsnip... maybe a root vegetable omelette would be nice (must try this!). You might want a green vegetable omelette in the spring - perhaps peas (or mangetout if you can get them that haven't been flown in from Kenya), baby broad beans, broccoli florets, asparagus tips or maybe a green pepper.
Whatever, you chop your vegetables into small pieces, and cook over gentle heat in a lidded frying pan - use cooking oil of some kind. Stir occasionally, but keep the lid on as much as possible to let the vegetables cook mostly in their own steam. If you're using frozen vegetables, thaw and slightly cook them in the microwave. If you're using bacon or chorizo or even mini-sausages, add them and cook them, too. When the vegetables are cooked, pour on a couple of eggs that you have whisked until they are all one consistency, seasoned, and maybe added some grated cheese to. Keep the heat low, and keep the lid on the pan. Cook gently without disturbing it until the eggs are set through. Cut into wedges and serve - perhaps with bread if you haven't used potatoes (I am incapable of eating anything eggy without some form of carbohydrate, a relic of having grown up in the 1950s!).