Cut bacon across into small pieces. Cook in a skillet until brown. Remove from skillet with a slotted spoon and set aside.
Season the veal cutlets with salt and pepper. Dust with flour. Sauté veal in skillet with bacon fat until browned on both sides and cooked through. Remove veal from pan. Cover and keep warm.
Melt the butter in the skillet. Add garlic and cook for a minute. Add the sherry and deglaze the pan.
Add the shiitakes, fiddleheads and reserved bacon, and cook for 5 minutes.
Divide the veal among 4 plates. Spoon the sauce over and serve immediately.