I also do another pitta filler which is special. It's a leftovers meal so you need to plan your picnic for lots of people OR after a family meal to justify it.
I get a huge roasting pan (the one i put the turkey in at Christmas) and put into it four aubergines, diced to 1" cubes, and 2 large or 3 small red onions, quartered or eighthsed (not a word i'm sure), season with salt, pepper and a slug of olive oil. Get a full leg of lamb and stab it all over and put peeled garlic cloves into the stab holes, also if you like it, little bunches of rosemary leaves. Stick the lamb on top of the veg and put the whole lot in the oven to roast very slowly for about 2 hours, then cover it with foil and roast for a further 3 or so hours, until the meat is melting from the bones. THen take it out, remove the bones and shred the meat with two forks, mix it all together. It is AMAZING served warm in pittas (you can take it hot in a tupperware, well-covered, and it will be warm by the time you want to put it in pittas) and very filling. You can drizzle a little mint sauce on once it's in the pittas for an extra zing. One leg serves about 10 people though, so definitely one for bigger parties. You can scale it down with a half leg but it doesn't work very well with leg steaks etc. as it needs the fattier bits to really melt.
Mmmm...i love food!