green beans blanched then stir fried with a little olive oil, garlic and parsley. (sometimes add some red pepper strips; looks very pretty.)
Ratatouille is good; lots of recipes on internet.
Like Nigel I roast a lot of veg (typically peppers, courgettes, onions, aubergine, garlic). Drizzle over a bit of oil, I often add a splash of balsamic and a sprinkling of smoked paprika.
(stick some seasoned chicken on top after about 20 min or a couple of fillets of fish towards the end (dot with butter/parmesan and dare I say a few breadcrumbs) and it makes a full meal.)
A brilliant (and very low carbohydrate lunch) is to split a spaghetti squash, put onto an oiled tray and bake for about 30-40 min (until soft). Carefully remove the hot 'spaghetti' strands with a fork and mix them with anything you might put on spaghetti (very simply cooked lardons and some cheese and maybe a little chopped (deseeded) tomatoes. Put the mixture back in the shells, sprinkle with a bit of parmesan and brown under the grill.