It doesn't matter how you eat your food. The small tins of flavoured tuna are really cheap, and a can on a bread roll , with a whole tomato (not cut up) as a side, and a lettuce leaf or two, can be a lunch. Most salad vegetables don't need to be cut up, and this can save your hands and wrists. I don't peel carrots. Salad vegetables that really need to be cut have been gradually eliminated (I always hated cucumber). I have been known to eat a whole red pepper. When I feel like it, I do cut up salad vegetables, I just don't feel obliged to.
Most of the year (not now, it's far too hot) for tea we have soup which we cook on Sunday and have until Thursday night, with slices of toast. On Friday night and Saturday night we have something different.
One of the advantages of these sorts of meals is that they also don't generate many dishes, so there is very little in the way of dish washing. The bowls get washed each night, and the soup pot gets washed when it is emptied on Friday, having spent the week in the fridge. SO really likes the Woollies Select box meals for one - for instance the Satay Chicken. We chop up some vegetables, nuke them for 3 minutes, and then add the sauce and nuke the rice at the same time, so it turns into a meal for two rather than one.
I am a fan of a sandwich press, which cooks just about anything you grill or fry without making a mess, and you just wipe it clean. Pancakes - just pour in some batter, put it on the closest setting, close the lid, and you instantly have a pancake (same for omelets...). Same with chips (they take a bit longer). When I was recovering from my accident, I really couldn't stand around for long, waiting for food to cook. My back would start to ache if I did any amount of stirring or cutting. If I sat down while food was cooking, I would sometimes go to sleep. Changing to the microwave and sandwich press as my main cooking implements was a game changer for me because they eliminated that problem area. When I had a bit of energy, I cooked a meal from the microwave recipe book and gradually learnt how cooking with a microwave (as against heating up) differed from conventional cooking, so now I can cook most things in a microwave. Of course, its biggest down side is the absence of browning - that's where the sandwich press comes in. This also means our energy bills are lower because we are using more energy efficient cooking methods.
I'm sure you've seen my chicken stock recipe - which again, eliminates having a stove top going for more than a few minutes, and you will note that it doesn't involve much cutting (the onion gets cut three times - and that's if I'm feeling like it - and not peeled). I grow most of my vegetables and all our fruit, so I preserve or freeze them after having cut them to appropriate sizes, which eliminates doing that work when I am not feeling up to it.