I tried freezing some, but unfreezing frozen lentils turned out to be way too annoying
I make what sounds like a similar lentil/tomato sauce, and freeze it as individual portions in small foil trays (they measure about 15cm by 12cm and hold about 400g or so of food). Those trays can go directly from the freezer to the oven, and 30mins at 180°C will generally suffice to defrost whatever.
Can of course defrost in the fridge overnight then heat the sauce through in a pan, but that requires forethought so I mostly don't. Have at times defrosted a frozen brick of lentils in a pan (adding a splash of water to help moderate/circulate the heat) but it is indeed quite annoying that way.
I have several other meals that similarly go from batch-cook to freezer to oven in the same foil trays, including a vegetarian lentil+mushroom shepherd's pie and a roast vegetable tagine (and also meat-eater options). Can supply recipes if interested.
Embarrassingly enough I don't think past me ever tried to defrost it in the oven. Tried to put it in the fridge the day before and then microwave, which was not very effective. Just too excited to use microwave even for things where I know they don't work well because my parents didn't use to have one that I did consider the oven for this. Currently I am sharing a tiny freezer shelf with 7 people, but I might try this in the future.
Currently, I am a bit unsatisfied with my food options in the suburbs of Melbourne, Australia. So this post is just me reflecting a bit on some of my favorite meals when I lived in different places and thinking about if I can find something better for my daily routines.
I am young and don't have any issues with weight, so my diet is pretty carbohydrate-heavy since that is cheap. I also prefer vegetarian food, since cheap meat tends to come from factory farming. I am not vegan, since I would be bound to get deficient in something, so this is my compromise. I still eat eggs since they are cheap and make me worry less about being low on some crucial amino acid.
I am a huge fan of Soylent-like meal replacement products that allow me to have a meal that is extremely easy to prepare, cheaper, and about as healthy as Ramen + Eggs. I tend to like really boring food, and I actively don't like adding too much variety (varying the ingredients) since I have a harder time making it a routine.
Gwern would tell me to just fry some eggs with some vegetables in a pan and to otherwise just cook some things in batches. His cooking habits appear to already be outside the window of what I would call convenient, though I would find cooking more convenient if I had a dishwasher.
These were my staple foods as a university student in Germany:
Really quick option: Satislent (Meal replacement shake which is cheaper and tastes better than Huel (~230kcal/$ if bought in bulk)). Cleaning the Shaker bottle would be annoying. My solution was to keep the bottle in the fridge and then rinse it when I used it again. Often, I would be forced to properly clean it. It's especially dangerous to forget the bottle in your bag, because the grain soup is the perfect breeding ground for bacteria.
Frozen Pizza (~400-600kcal/$ (The cheapest frozen Pizza in Germany tends to be really cheap). My main constraint in my dorm was freezer space.
Spaghetti with Red Lentil Tomato Sauce. I would make the Red Lentil Tomato Sauce in Bulk and then keep making Spaghetti every day. I didn't want to keep the lentils in the fridge beyond 4 days, so I couldn't make it in batches for longer amounts of time. I tried freezing some, but unfreezing frozen lentils turned out to be way too annoying (perhaps I should have gotten some freezer molds to get them into a small enough size instead of using the Tupper containers I used). Not sure what the exact price per calorie is, but it is cheaper than both options above and also has more protein and essential micronutrients than both options above.
Protein bread with Peanut butter or fresh cheese. When I still lived with my parents, we used to eat a lot of bread. When I lived alone, I was still giving bread a try, but I usually picked the whole-grain or added protein one. In both cases, the problem is that bread is quite expensive, tends to spoil quickly, and doesn't even taste that great. It is quickly prepared, though.
All of the above work really well as convenient foods, especially if you don't have a dishwasher and have to wash everything by hand.
When I was living in the Austrian Alps for 9 months, my staple food was crisp bread with cheese and pumpkin seeds (~330kcal/$). I don't understand how that stuff is not overtaking the planet? It has infinite shelf life, is cheaper than fresh bread + cheese (presumably because of the shelf life), requires zero preparation, and it tastes amazing! It is maybe a little dry, but I can just drink more water. Clearly, most people's food preferences must be very different from my own.
I also ate cereal with soy milk (0 sugar + extra protein). I like cereal, but good-tasting ones either have too much sugar or are too expensive (I might consider mixing my own cereal). Also, I couldn't find any soy milk that tastes as nice as the Austrian extra protein one.
Amazon had also started selling fully prepared German Lentil Stew and Chilli sin Carne, which I used to order, but that's also not available in Australia.
My current main staple food is Quota's Moroccan Cous Cous (~146kcal/$). It is delicious, warm, and healthy food that I can prepare by just boiling water in a water cooker. Amazing! I don't know why all the other complete food companies don't have similar products. It is a bit expensive, but still cheaper than other food for lazy people in Australia (the cheapest frozen pizza here is 4x the price in Germany).
It would be great to have something cheaper, or at least something different on the same Pareto frontier, for at least a little variety. Quota used to have a second warm meal, but they discontinued it before I had a chance to try it.
So I was brainstorming what I would ideally want, and I guess it is something like the cous cous where I have a warm meal, where I need to just put it in the microwave or add boiled water, but cheaper or at least something different from couscous, so I don't grow bored of it that fast. It needs to have a long shelf life, so I don't have to prepare it too often. I might be reinventing Oatmeal? I don't like the texture of regular oatmeal, and I also get an ick from warm sweet food (or most sweet things generally), but maybe that post is right and I just had bad oatmeal. I might want to experiment with salty oatmeal. If dried vegetables are too expensive, maybe I'll buy ones that melt fast (spring-onions?). There are probably similar things in this category.
I then thought maybe there is Pasta like Spaghetti that boils faster, but is cheaper than Ramen (I thought Ramen prices are a scam). Quickly asking a language model, I learned that Ramen is actually pre-cooked! Turns out, it would otherwise be quite hard to get pasta just by adding hot water to it! I guess Ramen isn't more expensive than Spaghetti for no reason after all. My understanding (which could be wrong) is, you could still make really thin pasta that you just add hot water to; they'd just always taste overcooked, which wouldn't be a problem for me, but I guess it would be for most people? Sort of like rice paper, but in pellets.
It would also be great to have better options than over-sweetened whey protein bars on the go. Perhaps I should also look for good cheese crisp bread options online. Jimmy Joy has great bars in Europe, but the shipping to Australia is too expensive.