From 1912:
Mince enough cold chicken to make a cupful and mix with it two tablespoonfuls of minced cold boiled ham and one of melted butter. Select fine peppers of uniform size, remove the stems so that the peppers will stand upright. Then cut a piece from the blossom end large enough to allow you to dig out the seeds. Do this with a pair of sharp scissors and do not let the seeds touch the sides of the peppers in withdrawing them. The peculiarly pungent taste, unpleasant to many, lies in the seeds.
Parboil the emptied shells for five minutes to make them yet more mild. Lay them then in ice water to make them firm enough to hold the stuffing. When they are cold wipe and arrange them in a buttered bake dish; fill with the prepared mixture and fit the scalded tops on again.
Pour about them a cup of chicken stock, made by thinning gravy from the roast fowls with a little water. If you have none, substitute a 10 cent can of strained chicken broth. Bake, covered, half an hour.
You may vary this popular dish by filling the prepared peppers with a forcemeat or crumbs, chopped pork, and tomato sauce; with rice seasoned with cheese; with cold minced fish or with French mushrooms, halved and mixed with a good drawn butter.