I read that batch cooking can be quite efficient: You spent a day every month cooking a huge amount of food that freezes well. Works especially well, if you are not bothered by eating the same meal for a few days in a row.
We've been 'Once a Month Cookers' for almost 8 years now. I swear by it, though my wife is starting to waver.
"eating the same meal a few days in a row" has never come into it. We batch cook 6 different meals by 4 portions = 24 dinners, and mark the calendar so we mix them up but don't have 3 quesadillas left at the end.
I'm not sure if we'll get to this point, though it interests me. We originally started as a cost-saving measure (I took a pay cut to move to a better city; mortgage; and a wife-to-be still at university), and my beautiful wife actually enjoys cooking so we'll outsource other time sinks long before food preparation.