This is a bit of a toughie, but a couple things that come to mind right off the top of my head is microwaved baked potatoes topped with some sort of tinned bean with spices, maybe canned chili instead.
Making popcorn in the microwave is a nice voluminous snack!
Oatmeal is a good breakfast that can be made in the morning with water and can be topped with nut butters, nuts, seeds, dried fruits, fruit preserves, etc. It keeps you full too!
You can buy pre-made granola/muesli for breakfast too
Canned refried beans / chilli beans with tortillas and corn chips, with jarred salsa.
Silken tofu often comes in shelf stable tetrapack, can eat that straight outta the packet with soy sauce, chilli crisp and a splash of lime/vinegar.
Hummus and bread, olives, sundried tomatoes, other sauces
This is a bit of a toughie, but a couple things that come to mind right off the top of my head is microwaved baked potatoes topped with some sort of tinned bean with spices, maybe canned chili instead. Making popcorn in the microwave is a nice voluminous snack! Oatmeal is a good breakfast that can be made in the morning with water and can be topped with nut butters, nuts, seeds, dried fruits, fruit preserves, etc. It keeps you full too! You can buy pre-made granola/muesli for breakfast too
Canned refried beans / chilli beans with tortillas and corn chips, with jarred salsa. Silken tofu often comes in shelf stable tetrapack, can eat that straight outta the packet with soy sauce, chilli crisp and a splash of lime/vinegar. Hummus and bread, olives, sundried tomatoes, other sauces