Baked potatoes + last night's leftovers are always a good, frugal choice. It's a great way to divide one piece of chicken and one cup of vegetables (with the addition of some cheese) between four people . . . and it doens't "feel" like the same meal rehashed.
Don't overlook sweet potatoes as a variation on the theme.
And if you can find some white sweet potatoes, buy them! Yummy.
Though hash is another good way to use up your leftovers.