Although the Disney animation hit of 2007 brought this term to the forefront of the American population the name refers to a French dish dating back to 18th century France.
The name is derived from the French words ratouiller and tatouiller which according to Alan Davidson (The Oxford Companion To Food) are expressive forms of the verb touiller which means to stir up. Further, Davidson states the first appearance of the word in English was found in Cassell's Dictionary of Cookery, 1877. Actually at that time the word was misspelled as 'ratouville' and referred to a meat stew. In the 20th Century later authors such as Heyraud described the dish as "a ragout of aubergine (eggplant) with tomatoes, courgettes (zucchini) and sweet peppers" eaten throughout Languedoc and Provence. This author also states that the name Ratatouille was given by the citizens of Nice.
No matter who is credited with the dish or the name it became exceedingly popular throughout France. Most agree the popularity grew because it was easy to make with abundant summer ingredients and that it could be served cold as well as warm.
Ratatouille derives its flavor from the freshest of vegetables. The best results will come from your own garden-fresh vegetables. If you don't maintain a garden then get the best you can from your local farmer's market or reliable grocer. Here are some selection tips for each key ingredient.
Eggplant (aubergines) - If you are using eggplant make sure to select medium sized fruits with dark, glossy skin. The eggplant should be firm and heavy.
Zucchini - You want small, young squash, not shriveled and make sure you can still see a fresh green stem end. If you have a garden then pick the squash the same day you plan to prepare the dish.
Sweet Peppers - Use bright colored red, yellow, or orange peppers, or mix them. Select peppers with firm exteriors, no soft spots.
Onions - Yellow dry onions or the sweet varieties work well (Vidalia, Maui).
Tomatoes - select small to medium size ripe but not "mushy" tomatoes. If you are trying to make this dish when tomatoes are out of season then good quality canned tomatoes will be better than the "flavorless" fresh ones at the store.