I freeze soups, curries, and sauces in those plastic deli containers. If you’re freezing something that goes with rice, freeze a container with a portion of rice too.
Then just take the frozen container(s) and put it in your lunchbox- voila, ice pack plus food.
You can freeze nuts to make them last longer. Also bread. Also hot peppers like serranos. If you have lemons that are going to go bad before you use them, juice them and freeze the juice.
Some leaves and spices that you get in large quantities, like curry leaves or kaffir lime leaves or lemongrass you can freeze the extras in bags until you need them again.
Not OP, but we have a bidet and a basket of cut up t-shirt cloths next to the toilet that are single-use and then go in the wash every week. I wouldn’t personally reuse washcloths for wiping out of fear of UTIs, but I’m extra paranoid.