Do you have any pointers to a meal plan that would give me full daily nutrition for say, a time/effort expenditure of around 20 minutes a day in preparation?
Let's say I'm totally cool eating the same thing for any given meal each day (though I'd prefer different breakfast/lunch/dinner within same day), and let's say I'm fine buying appliances as long as the maintenance/cleanup is within that time period too. Money isn't a concern here within reason. Since you mention rice cookers and crock pots (and I also have an instant pot) I can also work with set-and-forget as long as I only have to pay attention for 20 minutes or so.
The draw of Soylent to me is that I basically have no clue how to feed myself within time allotted, so I eat like crap grazing on what amounts to snacks or ordering out. I know Soylent isn't great but it's better than what I do on my own.
I'd love to have a healthier alternative, but I also know from experience that unless I can find something dead easy like described, I won't build the habit.
I like (again this is my taste, yours of course may vary) oatmeal, coconut and fruit bars (the internet is full of good recipes for energy, protein, fiber, etc bars and snacks). They last a while in the fridge, and basically forever in the freezer. Another case of, "Make it when you have some time, and eat them for the rest of month or quarter".
Finally... sandwiches, salads, and soups. I also love granola with yogurt and honey, and eat that as my "I have some time to enjoy this" breakfast; only thing to cook is the granola, again once a month or so.
I just wish I could actually find a decent and specific "sandwiches, salads, and crock pot" type 7-day (or even 1-day) meal plan out there that covered all the bases for times when I haven't done prep work. I'm a little lost as to how to combine the ingredients effectively--I know the concepts of nutrition, of course, but not the intersection of those and what practically works.
http://whoneedsacape.com/2012/11/crockpot-freezer-cooking/
https://onceamonthmeals.com/blog/recipe-roundups/101-freezab...
http://greatist.com/eat/super-surprising-rice-cooker-recipes
Edit: My best advice is to think about what you have to work with in terms of appliances and such, and google search for recipes using them, along with things like "For a month" and that kind of thing. So much of this is down to personal taste; I mean if you don't like black beans, no amount of recipes for them will help you out.
Breakfast - yogurt and frozen fruit blended into sherbet. I have 8 different kinds of frozen fruit in my freezer so there's plenty of variety.
Lunch - replaced by a protein shake at 11, then another one at ~2. I mix it with powdered drink packets, so there's plenty of variety there too.
Dinner - a crock pot with some kind of bean (again, I mix it up), a can of some kind of green (spinach/kale/collards/etc), some spices and some kim chi.
Elevensies (yeah, I'm like a jacked hobbit) - a piece of smoked meat and some sauerkraut.
The key is to keep the structure of your meals the same, and just have a rotation of ingredients that you swap out to keep things fresh.
It takes me at least an hour to cook and eat 3 meals a day. Soylent takes almost no time to cook and consume. If you value your time at all (say, a very minimal $20/hour) that's $600 a month saved right there.