In order to get variety at a sensible cost, I start with the Aldi super 6 (other super markets have similar deals). This week apples (eat for breakfast with peanut butter, cook with spices and add to porridge), celery (not keen on it raw so it gets finely sliced and fried up with onions), mangetout, pink grapefruit, red peppers and spring onions. Grill the grapefruit with cinnamon sugar, the rest is salad stuff.
Then add a few root vegetables, carrots and potatoes plus a selection from celeriac (grate into coconut based curries, it melts down in 40 mins and thickens the sauce plus adds a umami taste), swede (mash with tatties), parsnips (roasted or into soup), sweet potatoes (roasted, cooked in chilli sauce, soups or grated in chilli). If I lived alone I would probably buy a stew pack sometimes.
Some carrots get grated, seasoned with salt, pepper, lemon juice and a dash of olive oil (this week had shredded red pepper in it) - this goes in a box in the fridge and is added to wraps, burgers, sandwiches or just a spoon or two on the side of a meal.
Onions, brown ones are cheapest but we buy red ones occasionally as they have slightly different nutrients. Often have an onion salad in the fridge. This week's is a large mild onion, finely diced with some spring onion and grated radish, dressed with roasted garlic mayo and vinegar. Other times we have a variation on a slaw.
Plus random selection of other veg, usually mushrooms, some sort of salad leaf, green leafy veg.
Then you add in peas, beans and lentils. Mushy peas are fab.
Nuts and seeds, peanut butter without too many additives works fine.
Kimchi, sauerkraut, gherkins
Loads of herbs and spices as food should taste nice.
Wine and coffee count (in moderation)
Yesterday's fish finger sandwich had a dollop of carrot salad, fish fingers, onion salad, lettuce and gherkin (7 veg varieties) The portions were not massive but repeat all week in the same vein and it adds up.