I order a bunch of food from Harmony House. I'm sure there are other places too, this is just the first place I found. I started with their Backpacking kit, and then over time learned which foods I like better than others. Here is what my current supply looks like. My starches:
These are peas, butternut squash, sweet potato, and sweet corn. The corn is somewhat crunchy even after rehydration. Note I don't have potatoes here. I don't find the dehydrated potatoes to be very tasty, though I suppose I could give it another try.
Here I have pinto, black, lentils, kidney, split peas, northern and garbanzos.
Broccoli, cabbage, onion, spinach, celery, and "vegetable soup" which is a mixture of carrots, bell peppers, onion, and other stuff like that, all veggies.
I combine them into a big bowl with 1 part (by weight or measuring cup, doesn't matter) starches, 1 part beans, 1 part veggies. I just pick at random what I want from the 3 categories, or add some of all in. It doesn't matter much really, just make sure you have enough sweet potatoes and butternut squash because they make it taste really good.
Now, how much is a serving? For backpacking I wanted to make sure I'm getting enough calories, so I looked at the nutritional information for all these different dehydrated items. It turns out it's very similar for all of them, from starches to beans to veggies. Why? because all the water is gone. Veggies are mostly water and that's why they are low calorie. When you take out the water, they have a similar calorie density to dehydrated beans. Interesting, huh? So it turns out they are all about 3-4 calories/gram. 150 grams then gives about 525 calories. Or if you prefer ounces, it's about 100 calories per ounce of dried food. So if you want 500 calories per meal, that's 5 oz by weight per meal.
For my first backpacking trip, I put each meal in a small ziplock back and then packed those in a larger one. I decided that was wasteful, so now I just put all the food into large ziplock bags.
To rehydrate, add about 3 times as much water. You can use heat or not. If you use heat, bring it to a boil it and it will be ready in 10-15 minutes (I'd let it sit another 15 minutes after that). If you don't use heat, you can let it soak for 1-24 hours. I prefer at least 2 hours--I think it digests better the longer it soaks. Here is how I usually do it, whether backpacking or day hiking or flying somewhere: I put about 75-90 g of food into into each of two 16 oz wide mouth bottles and fill them to the top with water. I've put a mark on the bottle to fill the food so if I don't have a scale, I don't really need it, just fill to the mark and add water. I use a long tea spoon and eat right out of the bottle. It is so refreshing when backpacking because of all the liquid. I don't get dehydrated and thirsty like my companions eating dried fruit and salty snacks.
This is a very filling meal and it tastes surprisingly good--the reason is that the squash and sweet potatoes make it taste sweet. So these are key ingredients you don't want to leave out. And of course you can change the ratio of veggies to starch to beans to whatever you want. You can of course supplement your meal with any fresh fruit or veggies you can get your hands on, and also nuts and seeds and dried fruit if you eat that.