Rubaboo was a basic stew or porridge

Porridge

Porridge is a dish made by boiling oats or other cereal meals in water, milk, or both. It is usually served hot in a bowl or dish...

 consumed by 'coureurs des bois' and 'voyageurs' (fur traders) and Métis people of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, traditionally made of peas or corn (or both) with grease (bear or pork) and a thickening agent (bread or flour). Pemmican

Pemmican

Pemmican is a concentrated mixture of fat and protein used as a nutritious food. The word comes from the Cree word pimîhkân, which itself is derived from the word pimî, "fat, grease". It was invented by the native peoples of North America...

 and maple sugar

Maple sugar

Maple sugar is a traditional sweetener in the northeastern United States and Canada, prepared from the sap of the sugar maple tree.-Preparation:...

were also commonly added to the mixture. It is occasionally spelled Rubbaboo. Other sources describe it as consisting primary of boiled pemmican, with thickening agents added when available.