"The King preferred the old-fashioned early dinner, and a homely menu such as roast mutton, souercrout, brawn, two cowsheels and Ribbon Pudding, the Queen began, about 1806, to take luncheon. Chicken broth, lamb cutlets, two pullets and sandwiches were a typical choice. Mutton sandwiches had appeared in the lord steward's ledgers as early as 1784 and on the 5th January, 1792 the eight-year-old Princess Amelia, after dining off roast beef and plum pudding, ate chicken sandwiches with oysters for supper. In the early years of the 19th century sandwiches became a staple article of diet in the Queen's informal meals, which seem to have varied according to the King's wish. Sometimes she dined with him, sometimes she took luncheon and then a separate 'late' dinner at four, or on special occasions at six o' the clock."
Queen Charlotte by Olwen Hedley