Around two weeks per month I make a huge tray of roast veggies. Usually onions, peppers, tomatoes, courgettes, aubergines, carrots, butternut squash, marrow, spring onions, leeks, depending of what I have in the house. I put on the tray salt, black pepper, chillie flakes, paprika, garlic and oil (chillie and garlic oil if I have it). Towards the end I add a pasatta if I want to cook pasta with it.
Once it is cooked I can make pasta or lasagna with it. Or fry and egg and top it with it, maybe with rice or toast. Or use it as a side to some fish/ meat and potatoes.
Mix it with couscus for my work lunch.
If I want soup, I just blend them with a bit of stock.
If I want a curry, add chickpeas, curry powder and spinach, or coconut milk. My husband has tried ricotta in a curry recently and it was divine, I think better than coconut milk!
So, it is versatile, so it sees me through 2 or 3 days of dinners or lunches, and it keeps well in the fridge till I get to use it throughout the week.
I agree with PP, soups are a great thing to cook in bulk, specially now that it is getting colder.