My onion caramelizing left me with extras and I was imagining how to use them (they do freeze well, by the way) when the risi bisi post jogged my memory. Mujadara is a rice and lentil dish from the middle east, flavoured with onions. You'll need a fresh onion to make it this way as well as caramelized onions, and green or brown lentils. The red ones will turn to mush and result in a strange though edible dish. You can use any type of rice; leftover is easiest. If you use brown you will have to pre-cook it a bit since it takes much longer than the lentils.
Start by sauteing half an onion with a little salt in a saucepan. The oil you use doesn't matter much; I used leftover garlic and herb butter because I had a lot of it but olive or regular cooking oil would work fine. I am sure a fat free version of this would produce OK results as well, if you had a good nonstick pan. Ideally, you would be doing this slowly over medium heat - this is like the sweating that you do to vegetables before making a good soup. You don't want the pan too crowded, and you want to release and concentrate the juices from the vegetables (the salt helps) without turning them too brown. This stage gets the most flavour from the vegetables into the finished dish; the amount of time you simmer after liquid has been added doesn't have near as much effect.
Add a few shakes of cumin and 2/3 cup of lentils and 2/3 cup of rice, if you are using raw rice. Saute this combination, which should be getting very fragrant, for a minute or two and then add hot water or stock to about 2 cm above the level of the mixture. Let boil, then turn down and let simmer till rice and lentils are cooked, 15-20 minutes. Stir in a couple tablespoons of caramelized onions and let sit for a few more minutes for the flavours to blend. Taste and adjust seasonings.
If you are using precooked or leftover rice, add it at the same time as the liquid and don't add as much liquid - barely cover the mixture.