"I often read about what is a good diet, but I can't resist buying pies and pasties in the supermarket. They do smell good. I'm three stone overweight (and rising) and it's causing problems."
British supermarkets do sell good food (apparently other countries are not so good), but the top priority of their shareholders is profit. There is generally a greater profit margin on 'ready meals' than on fresh food.
I bought one of the pasties you mentioned, and it is better than most, (and tasted good), but beef fat, lard, white wheat flour and water make up most of the contents. Potato, onion and beef predominate in the filling.
Much of the taste, and aroma, was due to beef fat, onion and crushed black pepper. I could easily fancy one of these every day, and the only way to combine the pleasure with a healthy diet was to make my own. So I made seven :) I have to freeze all but one, or I'd soon be after another ... and another.
The contents, food analysis, taste and health benefits are far better than the shop-bought pasty, and, despite using top quality ingredients, much cheaper. I couldn't see much value or appeal in pastry, so I made twice as much filling and did without pastry.
1 onion, 2 large potatoes, tomato puree, diced turkey thigh, Sainsbury's frozen soya mince (lean meat would work just the same), sunflower oil, sunflower seeds, pumpkin seeds, black pepper corn (crushed), coriander seeds (whole), 1 teaspoon gravy granules added when nearly cooked.
Cook in a large, lidded casserole dish in microwave or oven. (I used the microwave). The consistency of this 'filling' makes it easy to form into pie shapes, or to freeze in pie shaped containers.
tip: rather than using 4 teaspoons gravy granules, use 1 gravy and 5 tomato puree - it makes a similar texture to gravy, but far better nutrition (thanks for the tip, P).
Clearly you could vary all the ingredients to suit your taste and for variety. This example worked really well, and I'll be cooking some more when these run out.
Despite using the best ingredients, and doubling the amount of filling, these turned out less expensive than the bought pasties.
To make a complete meal, cook fresh veg to go with the 'pasty'. e.g. peas, broccoli, carrot, ...