Cooking a whole meal every night can be a hassle, when there's only one, but you don't have to cook every single night.
Freezer foods are the answer.
Single portions, frozen in suitable containers, to be thawed and reheated.
Choose a day (or a weekend) when you know you are going to be home all day and have nothing else planned and get cooking.
A blade roast about 1-1 1/2 kg should give you 3-4-5 meals depending on your appetite.
Buy packets of filled pasta such as ravioli in sizes that serve four,
separate it into four equal serves and freeze.
Buy (and heat) a jar of spaghetti sauce, jazz it up with added extras, (extra garlic, extra mushrooms, extra whatever you like), divide it into four portions, to go with the four raviolis, and freeze.
If you fancy a tuna mornay, make individual ones, eat one and freeze the others. Well covered of course. Reheat thoroughly after thawing.
Stir fry some spring onions and shredded carrots,
Add some shredded ginger, a small can of tuna, (drained), a little soy sauce,
then half to one cup of cooked rice. Eat half and keep half for the next day's lunch.
Naturally you don't have to be cooking all these things in one day or even one weekend, but if you choose a day a week for cooking and freezing, you'll soon have a variety of meal choices in your freezer.
Simply choose one each morning to thaw ready to be reheated for your dinner.
There are many other options. Make pots of soups and freeze, by frozen pizzas, add your favourite extra toppings, bake the pizza then wrap and freeze half for another day. Ready made frozen dinners are another option, Lean Cuisine make a good range.
None of these things will keep for extended periods of time, but you should be able to eat from your freezer for several days or a couple of weeks before having another big cook-up.
Of course you can have a night with scrambled eggs on toast, get a takeaway from a restaurant, have a fish'n'chip night.
In hotter weather, a fruit platter is a great option, add salad ingredients such as cucumber and tomato, a hard boiled egg for protein and most of your nutritional needs are covered.
In these days of ever rising prices, fruits and vegetables are still relatively cheap, and better for you than tea and biscuits. Mmmm, grapes....bananas....apples....