Let the olive oil and butter get hot in a stew pan, fry the beef cubes brown on all sides, add the onion and sage, stew until golden. Season with salt and pepper.
Then dust with 2 tablespoons of flour and stir everything well, add lukewarm water and add the stock cube.
Cover and simmer in the oven, preheated to 160 degrees, on the middle shelf for 2 hours. If necessary, season again with salt and pepper.