Microwave ready meals.
My local council does meals on wheels to anyone who wants them, check your local council.
Kippers - put the bag in a jug and add boiling water.
Toaster bags, as previously mentioned, and you can also toast potato waffles.
Beans on toast - toast in the toaster beans in a glass jug in the microwave - easier to pour from a jug. You can also add cheese.
Do you have a slow cooker? Prep in the morning before it is too hot or in the evening and keep in the fridge - don't put the actual pot in the fridge, it needs to warm up.
You can cook a joint in one, no prep just put the joint in and put the lid on - serve with bread and butter or make into wraps adding salad.
Or chicken pieces and potatoes. Pork ribs in passatta with tinned bertolli or broad beans.
Breakfast muffins - can be eaten anytime, basically beat some eggs and put in a muffin tray with any 'filing' you like, cooked bacon and sliced spring onion is my favorite - bake for 20 mins and either eat hot or leave to cool as a sort of quiche without pastry.
Pasta can be cooked by pouring boiling water over and leaving with a lid on for 20 mins. Put a tablespoon of cream cheese in a bowl, add a dessertspoon of the cooking liquid and stir - drain the pasta and put it in with the cream cheese.