For beans, I am able to buy various types in cans which are in only water, no salt or sugar added at all. I am too lazy for soaking dried beans tbh, and beans are a 'fast food' for us when for some reason we get in too late or whatever and I have to throw something on the table in moments. Check in your shops for beans/chickpeas etc in water only. I do same for sweetcorn (we also have frozen corn and fresh corn but the canned is again our 'fast food' when needed)
for bean or veggie burgers, I just experimented like a sort of pancake mix. Either add mashed beans to the mix or reduce milk/water and whizz the beans which makes them quite liquid. A small amount of flour and an egg with bind almost anything together, left over veg, beans etc to fry as fritters, once they are all fried, cool then freeze. Or if you have a mini muffin tray you can bake the mixture in there making nice individual portions. Even with beans you might find you need to try out different ones, mine wouldn't eat kidney beans for ages and ages, they are the cheapest bean here so i was quite keen to include them at one third the price of other beans. Mine liked a bit of herbs, spices or tom puree in his burger mix. You can't really go wrong if the mix is very loose spoon it like pancakes, if it is thick roll into patties, or use the muffin tray.
