...except when I don't!
Without a shadow of a doubt, cooking from scratch is much, much more frugal than buying per-made, convenience foods or ready meals. However, sometimes I have to work late, or forget to take what I need out of the freezer, or just don't have time to squeeze in a shopping trip. On those occasions, a convenience food or ready meal can be a whole lot more frugal than my other option, which is to get a take away.
I try hard to plan carefully and not let that occur very often, but when it does happen there are a couple of quick, easy meals that I can fall back on. Pizza is the first thing that springs to mind. In my book, there is no such thing as a bad pizza! Having a couple of frozen pizzas to hand can be a budget saver, providing me with something quick and easy to dish up. Even buying pizza from the local shop and cooking it at home is just as quick, and a lot cheaper than buying a take away. Also, pizza makes a good meal to offer any unexpected guests.
A jar of pesto and a packet of pasta in the cupboard means that I always have a quick meal on hand. I can usually scrape up a bit more to add to it, such as some veg, cooked with the pasta (even if its just a few peas out of the freezer), or some grated cheese, or a couple of chopped up bits of ham, or a tin of tuna, but even if I have nothing else, no one in my house would turn their nose up at pasta and pesto.
Convenience foods can sometimes be more frugal than the alternative, but I need to be careful that they don't become a regular part of the menu!