Cut the potatoes into slices and set them aside in a deep container with water so they don't darken. In the meantime, cut the onions and carrot. Heat the butter with a little oil or olive oil in a pan and add the chopped onions and carrot.
After they've braised a bit, add the meat. Once it's reddened too, pour in the water and broths and cover with a lid to simmer.
After the meat has simmered a bit, transfer it to the tray with the potatoes and pour in 1/2 cup water. Cover the tray with foil and bake at 356°F (180 °C).