Cut pocket in veal chop. Lightly salt pocket. Place layer of spinach in pocket and top layer with Fontina and Parmigiano Reggiano Cheese. Seal with a toothpick to hold mixture in pocket. Lightly dredge stuffed veal chop in flour. Salt and pepper outside of floured veal chop.
Melt 2 tablespoons butter and olive oil in cast iron pan. Place veal chops and sage in pan and sear for 2½ minutes per side. Add tomato paste in middle of pan and pour wine over tomato sauce, stir together and cook until reduced by half (approximately 3-4 minutes). Add remaining 2 tablespoons of butter and whisk into sauce. Add chicken stock, salt and bring to boil.
Cover pan and place in oven to roast 15 minutes. Uncover pan and roast another 8-10 minutes. Remove from oven. If sauce is too thin, thicken by putting on burner over high heat for about 1 minute.
To serve place veal chop on plate and drizzle sauce on each veal chop.
Recipe by Tout va bien! (tm) at https://christymajors.com/veal-chops-stuffed-with-fontina-cheese-spinach/