Ratatouille is a traditional vegetable stew which originated as a poor mans dish in nice. That may well have been its humble origins, but the stew has gone on to be known and loved, around the world and can hardly be considered as food for the poor today, though it is still a relatively cheap food if the vegetables are bought in season. It is imperative when making this dish to ensure you stick to its roots in the south of france where peppers, tomatoes, and garlic all grow in abundance. Use any color bell peppers you prefer, from brown to green, and anything in between. Also, use only good quality olive oil (if you can get french extra virgin oil from provence, even better though not imperative) as this contributes to the overall flavor of the dish. The danger with cheap oils, especially those not from france, is they can taint the taste and the dish will also lack authenticity. This version lightly caramelizes the onions and peppers before adding them to the rest of the dish, giving it a fantastic complex flavor without much additional effort. Finally, one of the secrets to making a perfect ratatouille is, do not stir too much or overcook so all the vegetables merge.