Camping

For convenience I like these. Posh baked beans particularly.

https://www.firepotfood.com/collections/firepot-dehydrated-meals

Army ration packs look grim. Do you like to cook (ie have some experience, interest and skills) or do you want the easiest/simplest solution? Are you riding somewhere you'll be able to get some bits (i.e. if you're going past a shop that sells pasta and veg then weight isn't that important if you're only carrying it for 20 minutes) or do you need to be self-sufficient?

Idahoan Instant Mash, Lidl/Aldi cooked lentils in pouches, angel delight, curry / Dahl pouches, dates, tinned veg (already cooked, so dinner is ready sooner)+ tinned tomatoes and some herbs, rice noodles (ready a lot quicker than pasta). Microwave-able rice takes 2minutes on stove.
Chocolate custard powder and dried fruit.

If you buy readymade hiking meals, I'd stick to the puddings, or totally avoid anything that has mash as a component.

Sainsbury's do powered milk, if you want it for breakfast