Ask your butcher to grind a good piece of beef.
Heat a frying pan with olive oil and grill the sage leaves in it adagio with salt and pepper. Turn them over after a few minutes. When they look nice and golden, place them on a sheet of kitchen paper to absorb excess oil. Let them cool then crumble them. Do not wash the pan.
Mix half of the crumbled sage, the meat, a little salt and pepper and form a hamburger.
Heat the same skillet, removing some oil if there is too much. Cook the meat and serve with the rest of the sage and some more ground pepper.