Just like the title says, whatcha cookin?
I am originaly from the mountains so this river running has come to me late in life, however the principals of packing a backpack are the same as packing a canoe or kayak for a couple day trip with no resupply and traveling by boat is a lot eaiser on the knees.
I still cook on a backpacking stove (pocket rocket) and go with dehydrated where boiling water is about all you need to do.
One of my standbys is the pasta side dishes like the Knorr alfredo (about a buck at Wally World). If you empty the contents into a qt freezer bag at home, add 1/6th c of dehydrated milk, and a tsp of butter buds, you are done with prep. When you are ready to eat, boil 2c water and dump the contents into the pot, cut the heat back and simmer for about 4-5 min, then cover and remove. Set the pot aside and either put a towel around it or leave it be and it will finish cooking in about 8-10 min in warm weather. A 8oz can of chicken or shrimp can be added after the noodles to get a little protien and flavor. If you are a self inflicted herbivore, you dont add the meat and its still a tummy filler.
One I just tryed was the red beans and rice side with store bought "beef crumbles". That involved no additional work at home, just boil, add beef, cover and wait and it was good. I like red beans and rice and it was better than just camp good.