My chickens don't free range. That's why I thought I needed to forage for them and provide them with some raw vegetable matter. I give them kitchen scraps/peelings, shredded cabbage ('cause Trader Joe's makes that convenient and relatively cheap), raw pumpkin ('cause I've still got a few on the vine), garden trimmings and weeds. And then some occasional BOSS and mealworms or some cooked egg when my husband doesn't finish his brekkie and if my cat doesn't finish her canned food I take them that as well.
I skip starchy things like bread, rice and potatoes -- though the occasional cooked bits turn up when I scrape plates. And if I have corn on the cobb -- which isn't often -- I'll let them pick at the whole thing.
My girls don't free range either-one of the few flocks who doesn't. They have a roomy coop, but stay outside most of the time in their roomier pen that is totally roofed and secure (electric fencing around it and dig proof. We have sooo many predators, but the ones I worry about most are the hawks and eagles. Having a beloved bird torn apart by one of these winged predators is not what I want for my small flock. So I am always looking for ways to imitate that foraging that they would get outside the pen. Any other suggestions than those given would be appreciated.
BTW, I was thinking a couple of my girls were getting a little chunky (my BAs), but when I picked them up to weigh them, I found it was all feathers! They're definitely ready for our cold winter!