This is a very colourful, and tasty vegetable side dish, and very easy to prepare, with a flair of a traditional French to it with the braised lettuce. Cooking lettuce might seem a jarring idea, but the French do cook lettuce as well as eating it fresh.
To save time, you could just use 1 pound (450g) of frozen sliced or diced carrots instead. If using frozen diced carrots, your cooking times may be less as the diced will cook quicker. Optional: season with a few pinches of an herb such as thyme or basil towards the end of cooking.