1 courgette (zucchini) per person
1 beefsteak tomato per 2 people
1 medium onion per two people
Salt, pepper, etc, to taste
Wipe and slice courgettes. Pour boiling water over tomato(es) and leave for one minute or until the skins split. Peel, and chop. Peel and chop onion.
Place all these vegetables in a saucepan and heat very gently until the juices run. You can gradually increase the heat as it gets more liquid. When it is liquid, season to taste, bring to the boil, and simmer for about 10-15 minutes (I always allow 40 minutes' total cooking time for this, but I think it does with a little less).
This is gorgeous over pasta, or if you have a meal that wants a little "gravy", e.g. grilled or microwaved fish fillets, or even steak You can also use it as a filling for lasagne, perhaps with some mushrooms added...
You can, of course, add to this an aubergine (eggplant), previously wiped and sliced, in which case it is ratatouille. Or you can use a vegetable marrow instead of the courgette, but you need to remove skin and pips if you use this. Some say it has a better flavour than courgette.
Some people advocate sprinkling the sliced courgettes and aubergines with salt and weighing them down for an hour, but I seldom do this - it is definitely unnecessary if the vegetables are home-grown.