What sandwich does Roo's mother occasionally make him in the book "Winnie-the-Pooh"?

Roo is a fictional character created in 1926 by A. A. Milne and first featured in the book "Winnie–the–Pooh". He is a young kangaroo (known as a joey) and his mother is Kanga. Like most other Pooh characters, Roo is based on a stuffed toy animal that belonged to Milne's son, Christopher Robin Milne, though stuffed Roo was lost a long time ago.

Unlike many of the other characters in the Pooh books, Roo does not have a known favorite food, although his mother (Kanga) makes him watercress sandwiches on occasion. He dislikes the extract of malt that his mother gives him as "strengthening medicine" after meals, though he will reluctantly take it.

Roo participates in the adventures of a teddy bear called Winnie-the-Pooh and his friends Piglet, a small toy pig; Eeyore, a toy donkey; Owl, a live owl; Rabbit, a live rabbit; and Christopher Robin, a human boy. Roo is introduced in the chapter entitled "In Which Kanga and Baby Roo Come to the Forest and Piglet has a Bath." Roo's friend Tigger does not appear until the sequel, "The House at Pooh Corner". The character Roo would subsequently appear in various cartoons and other adaptations.