There was a prominent lack of mention of @jacob's promoted stirfrying amongst what I shared of East Coast United States colonial food cultures above, but I imagine stir-frying as staple technique might have a beachhead--and would be interested if anyone ever comes across a similar cultural-historical analysis--of West Coast North America whose modern-day influence on culinary patterns can't be ignored, where while there have been some notable misses: spirulina (which the Aztec called "rock shit") and a relentless fondness for chia, I mean still, can we imagine a world without burritos and avocado toast? Is life worth living?
But I like some of these food histories because you realize how.. bad.. daily slop was (and not just because it was British!), as the account I shared had guests actually refusing to eat the food -- it is hard to imagine arriving anywhere in the developed Mondelez-distributed world and preferring to skip dinner. I mean we're not slurping spoiled milk and livestock feed for dinner, you know--and I guess I see these historical accounts as corrective digestif to my tendencies toward romantic primitivism and localism, wherein okay, fine, probably a Mediterranean diet (I mean Kloppen, not waterfront) was always vibrantly better and will always be (although I've always had a soft spot for my conception of Salish or maybe Tlingit cuisine where you're gorging off cedar-smoked salmon and huckleberries every day--if maybe you are lacking a proper bagel to put it on) but of course the modern cosmopolitan menu is more satisfying and varied and maybe worthwhile despite the vast amount of brainspace I have hence devoted to harboring opinions about Icelandic vs. Australian licorice, sourcing coffee beans over four continents, and casual culinary literacy assuming distinctiton between burrito, taquito, egg roll, spring roll, summer roll, mu shi, crepe, rotolo, dolmade, blintz or wrap (actually, can I have that brainspace back please?)-- which speaks to @jacob's point about globalization offering us the Best of All Possible Worlds, and not to Consider the Lobster too much here, but I don't want to minimize the real cost (not least in energy which I'll get to), nor the undesirable side-effects of that globalization as even Dr. Pangloss noted that with chocolate from the New World also came syphilis (sometimes in the same transaction), but more broadly as a good banh mi is a pretty perfect menage a trois of fussy French crustiness enlivened by pragmatic Vietnamese application of pentatonic Chinese philosophy, even for that pinnacle of the art of sandwichcraft, it took actual, real violence to get to that and to be quite aware to the consequence that there are people not in the world today because of it.
I mention this to bring it back to the OP's initial intent which I thought was pretty interesting, to think about the energy-intensivity of the cooking choice, and it may help to distinguish total energy from individual effort here as watching how that tracks through history might explain why it made sense to burn megajoules of tree to keep a perpetual stew going all day, which while it might make sense from a systems perspective integrating home heating, laundry drying, rendering barely-palatable foods edible, avoiding laborious fire-starting, it seems pretty wasteful to a modern eye to be cooking for hours.
I suppose that's all a inevitable result of transitioning up the energy ladder going from a world where it actually sounded reasonable to chop down a tree in your backyard with an axe to burn it for heat, sending however much of it up the stovepipe, as we have now transitioned to more efficient sources like coal and then oil, and then gas, getting more and more efficient at each source, which now themselves seem awfully inefficient as I'd hesitate to be cooking with gas, preferring instead to combust large amounts of diesel to mine polysilicon which is then subjected to burning metallurgic-grade coal in order to produce photovoltaic panels shipped by bunker fuel and gasoline to me where where they can power my induction-range cooktop except when it's cloudy. This is progress.
That in mind, I have an initially lidless crockpot I picked up on the street which looks like it is from 1978 or at least has a sticker on it suggesting the removable crock was noteworthy at the time and I use this portably, a bit like @jennypenny does to heat her greenhouse, or in my case warm up a drafty corner of the room while I write ERE posts (paired with another 110V turkey-roaster-like oven for baking use) and produce dinner at the same time, however I don't mean to bring a gun to a knife fight, but these crockpots are burning 100-150 W/hr and one of the beauties of @conwy's method is that you're only firing up the stove for 5 minutes or so, maybe 100-200W total, and well, I have to say it, why not just go pressure cooker at that point?
Is leaving a crockpot on for 6 hours any easier than flipping a pressure cooker on for 10 minutes and then forgetting about it until dinner?
(you can reheat to serve).
do think, from a culinary perspective, about what goes in before and after pressurization.
I would also consider nutritional impact as at least at one point I'd sourced actual peer-reviewed papers that nutritive content was better from pressure cooking due to shortened cooking times despite higher temperatures.
I have the crockpot, but if I'm not getting cold feet, on a daily basis I usually use the pressure cooker, like @conwy suggested with induction heating (although electric resistance coil is likely more efficient here) where I'll take 15-20 minutes (timed programmed cook for the induction cooktop so I don't forget, something roughly like that for electric coil range), which works for beans/large pulses to be drained and then seasoned, can get by probably 10m for lentils, and then honestly I usually just leave the pressure cooker on the range but if I'm feeling thorough I'll stick it in a haybox which is an old Coleman cooler.
You could drastically simplify this by just buying an Instant Pot, but my way works when the power goes out..
and I cook with gas.
or woodfire.