I am really into quality food cheaply, it makes me feel good to know I am using thing other people do not and getting better food as a result almost for free. The following things can all be done well within your budget assuming you have access to a fridge/freezer and a stove. In practice if you don't have the storage facilities, you can do the same things, just scale down the sizings. I live on my own too.
some ideas for you
Bone Broth
One of the best things for you is bone broths. Find a local butcher as the supermarkets don't do this . If you ask the butcher he will set aside bones from all sorts of animals for you. lamb, beef, oxtail, chicken. I usually take whatever he has .Chicken is the best one because you get more from it.
Chicken broth
When the butcher joint chickens, the carcass is left behind. Butchers keep there because they can sell them to the abbattoir and they are then put into animal feed.
The meat remaining on a chicken carcass is just as good as any of the meat on the legs of breast and depending how good a butcher he is, there may well be a lot of meat left on the bones, which will almost certainly include much of the offal which is also extremely good for you
Today I went to my local butcher and asked him for bones. He sold me a bag of chicken carcasses for £2.00. When I got home I found there were 7 carcasses inside. I put each one in the oven to roast as one would a normal chicken. After it had been cooked I ate one - Henry V111 style with a salad. It yielded 130 gm of good quality meat.
In total I have stripped 900 grams of meat off the carcasses which at 100 gm per meal is 9 meals.
There was a lot of fat and juice remaining in the oven pan. I filled a jam jar with each. One will be used to cook with, the other to add flavour to future dishes. The meat has been divided into 100g packs for the freezer which will form the basis of 8 more meals.
I then to added the carcass bones into a stock pot along with an onion, a couple of cloves of garlic, some apple cider vinegar and 7 pints of water. That will simmer overnight before it is strained. That stock will then be used either as a bone broth stock, or as the seasoning in any meat based dish. The volume will depend on how much I reduce the stock and intensify the flavour. The stock itself will turn into a nourishing gel when its cold. There will be at least 4 pints of it - enough to make at least 10 soups or meal bases .
Thus for my 2.00 I have got the basis for - two weeks frying, concentrated flavouring for at least 2 weeks of cooking, Enough main chicken to be the basis of 9 meals and enough stock to make a dozen soups. The actual protein part of my meals for the forseeable future will be costing me less than 10p per meal.
LIVER AND KIDNEY
For some reason , these are not popular in the UK, which is a pity as they are some of the best foods for you and its very tasty.. I always keep an eye out for these on the butchers counter in the local supermarket. A couple of days ago I bought 400 grams of lamb liver and 600 grams of beef kidney. The total cost was £3.60 ( from Waitrose!) I have since divided this into 10 100g bags of mixed meats for the freezer. So the basic cost of that will be 36 pence per meal. These can be fried with an onion and some vegetables, or used as an accompaniment to eggs, there are hundreds of recipes out there for offal.
VEGETABLE BROTH
Nothing in my house gets thrown away. every couple of weeks or so, I take all remaining vegetables, off whatever type and put them into a stockpot along with various spices and seasoning and some coconut oil and cider vinegar. Again with about 7 litres of water. I leave this to cook and then reduce to about half. I then blend and store in the freezer.
OXTAIL
Much underrated - usually on sale for around £7 per kilo, makes a great stew, enough for at least 6 people, plus a bone broth. i usually cook as a stew with some vegetables, but then remove the oxtail separately so i can drink the stew freely and add in a set quantity of meat depending on how much protein I want in that meal.
With the above ingredients I can feed myself a satisfying meal full of flavour for less than £1 per meal . One can vary flavours by combining the two broths, adding additional spices, I often do that then add some mustard and cream to create a really satifsying base , with some freshly cooked vegetable and one of my 100g portions of meat.
I have spent £7 on the protein content of the next 30 ish meals leaving the remainder for the vegetables, seasonings , mustard, cream and eggs.
I hope this helps !