In a re-sealable bag, combine flour, paprika, garlic salt and black pepper. Close the bag and shake well; set aside.
Pat dry the veal cutlets with paper towels.
Place plastic wrap on a cutting board before placing a cutlet on it; cover with plastic wrap. Using a meat mallet, pound it down to about ½-inch thick.; repeat with the others.
Working one at a time, add a cutlet into the flour mixture, close the bag and shake it until the meat is well coated. Shake off the excess flour and transfer to a plate while doing the others.
Preheat oven to 375ºF and grease a 9x13 baking dish; set aside.
In a large skillet over medium high-heat, add 1 tbsp. clarified butter and 1 tbsp. oil. When hot, working in batches, put in a couple veal cutlets; sear them for 1 ½ minutes per side. Transfer them to the prepared baking dish.
When the cutlets are done, add another tbsp. clarified butter and 1 tbsp. oil to the skillet; reduce the heat to medium. Add shallots and sauté for 1 ½ minutes.
Add mushrooms, sprinkle on a pinch of ground sea salt and cook until golden brown, about 5 minutes. Halfway through cooking, add lemon zest; continue cooking the ingredients.
Add garlic and sauté for 1 minute. Pour in wine and heavy cream; stir and simmer for 5 minutes.
Meanwhile, in a large pot over medium-high heat, add butter and when melted, add the spinach, stir well and cover for 30 seconds. Stir again and cover; this shouldn’t take more than 1 ½ minutes to wilt the spinach. Transfer to a colander to drain.
While the sauce simmers and the spinach drains, combine Parmesan and Mozzarella cheese in a small bowl; mix well and set aside.
To assemble the dish, evenly spoon the sauce over the cutlets before placing the spinach on top of each. Sprinkle the cheese mixture and parsley on top.
Transfer to the preheated oven and cook for 10-15 minutes or until the internal temperature reaches 165ºF and the cheese is lightly browned.
Remove from the heat and serve over spaghettini.