Fondant base: Bring milk to a boil. In another pan, melt butter; add finely chopped, pre‑cooked spinach (squeezed completely dry). Stir in sifted flour to make a roux.
Cook & season: Gradually whisk in the hot milk until smooth and thick. Season with salt, pepper, nutmeg, and Parmigiano. Spread in a parchment‑lined half‑sheet pan; chill until fully set.
Portion & bread: Cut into neat squares. Dredge in flour, dip in beaten eggs, then coat with panko. Chill 20 minutes to set the crust.
Prosciutto chips: Bake strips on parchment at 325 °F for 10–15 minutes until crisp. Cool.
Fry & serve: Fry fondant at 285 °F until golden. Drain on paper towels and top with prosciutto chips. Serve immediately.