Cut the meat into pieces, season to taste. Turn the slow cooker into baking mode for 60 minutes, pour oil and let it heat for a couple of minutes. Put in a slow cooker and fry on one side for 5 minutes.
Turn the meat over and brush with mayonnaise.
Cut the onion into rings and lay on top of the meat.
Cut the tomatoes into slices and put on the onion.
Sprinkle with grated cheese. Cover and cook off.
French turkey in a slow cooker is ready to sprinkle with herbs before serving.