One of my favourite dishes to cook, which is also pretty easy, is a paella. In fact, I made one the other night, took about 15mins prep time, then not long to actually cook.
I used smoked cod, jumbo prawns, spring onion, sliced lemon, chorizo, ginger and paprika.
Dice the cod into small chunks, and cut the chorizo into strips. Have some rice boiling whilst that's on the go, and by the time you've finished preparing everything else, the rice will be done.
Into a wok (use something appropriate if she doesn't have one) add some olive oil, and warm that through. Add the chorizo only to the oil, and leave this for a couple mins, keeping an eye on it to ensure that it doesn't get too crispy. What you want here is for the juices from the chorizo to start appearing in with the oil.
Add the rice, and stir this in. The juice from the chorizo will give the rice a lot of flavour, as well as edit the colouring. Add the rest of the ingredients, occasionally sprinking and mixing in the paprika and ginger. If you don't use sliced lemon, I'd recommend bottled lemon juice instead, as that will really create a good tang to the mix.
You can cook this for 5-10mins, it doesn't take too long. Keep stirring though, as that will allow the flavours to penetrate the rice, which is the bulk after all.
How you serve is up to you, and really depends on how much you done. I kept everything in the wok, and put placemats down to rest it on, and allowed people to just take however much they wanted. Leaving it in the wok kept it nice and warm after all, whereas if you just piled it onto plates, it would lose heat quickly.
All in all, it's simple to prepare, and surprisingly cheap. I paid around about £12 for everything, so say $20.