My chickens get pretty much whatever leftover starch we have, in moderation - bread, potatoes, rice, barley pilaf, etc. When the weather is a cold as it is, they get hot oatmeal in the morning, tempered with a little milk (or yogurt, if availlible). This is usually prsented with greens - wilted lettuce, leftover chard, whatever comes out of the kitchen. They also ADORE meat scraps, particularly suet and gristle, cooked enough to kill whatever pathogens may be present. They also love leftover eggs in whatever form from breakfast, even more is its something like quiche with other add-ins.
Feeding kitchen waste has cut my feed bill about in half, and my girls are happy and healthy. I only feed them real food, not processed garbage, but since that what I cook with, it's not a big deal to provide. A nearby deli also provides plenty of leftover greens, tomatoes, and other veggies, and also cheese that the girls adore. Yeah, they eat a fair share of layer pellets each day, but I find that they are happier with a diet that has variety, and carefully adding garden and kitchen waste to their feed bill seems to have a salutary effect on their health - they have no parasites, no deficiences, continue to lay happily depsite the season and atrocious weather, and convert animal-based protein to a useful, compostable byproduct.