Cut the veal slices into medallions and pound them thin using a meat hammer.
Dredge the pounded veal in flour seasoned with salt and pepper. Set aside until needed.
Saute the mushrooms in olive oil over medium-high heat until they’re almost fully cooked. Add the floured veal to the pan.
When the veal has been cooked on both sides, add the marsala to the pan. This will deglaze the pan and stop the cooking process. Remove from the heat.
Add the chicken stock, and seasonings to the pan. Reduce the heat to medium and continue to cook allowing the sauce to reduce.
In another saute pan add in a little olive oil and the baby spinach, saute until completely cooked and set aside (make sure you drain off any extra oil)*you can use water instead of oil if preferred.
Take the butter and coat it in flour pressing flour into the butter and add to the sauce (this is called a beurre manie) it will thicken the sauce and the butter will impart a rich flavor
Turn the heat to low and top each veal medallion with thinly sliced prosciutto and shredded fontina cheese
Cover the pan and allow the cheese to melt.
Place a portion of the spinach on a plate and place the finished veal saltimbocca on top of the spinach.
Serve with potatoes, rice, grains or over pasta and enjoy