Presoak a clay pot, top and bottom, in water for 15 minutes.
Combine the flour, thyme, sage, marjoram, salt, and pepper thoroughly in a paper bag, then add the steak and kidneys and shake. Set aside any leftover flour mixture.
Heat the bacon fat in a frying pan and brown the steak and kidneys. Place in the presoaked pot.
In the same frying pan combine the chopped onion,