Potatoes roasted whole, or cut to very large chunks if large, in meat fat along with the roast. Known from references in the 18th Century, the earliest receipt is in 'Apicius redivivus, or, The cook's oracle' by William Kitchiner

Original Receipt in Kitchiner 1830;

Potatoes roasted.- (No. 109.)
Wash and dry your potatoes (all of a size), and put them in a tin Dutch oven, or cheese-toaster: take care not to put them too near the fire, or they will get burned on the outside before they are warmed through.
Large potatoes will require two hours to roast them.
N.B. To save time and trouble, some cooks half boil them first.
This is one of the best opportunities the BAKER has to rival the cook.

Potatoes roasted under Meat.- (No. 110.)
Half boil large potatoes, drain the water from them, and put them into an earthen dish, or small tin pan, under meat that is roasting, and baste them with some of the dripping: when they are browned on one side, turn them and brown the other; send them up round the meat, or in a small dish.