Preheat oven to 350F.
Toast bread until golden. Place toasted bread in food processor and add pine nuts. Pulse-grind the bread and nuts into crumbs. Pour crumbs onto plate and combine with thyme and parsley (reserving a sprinkle for cauliflower), half of the grated cheese and zest of 1 lemon. Halve the chicken breasts across and gently pound them out between parchment or plastic wrap. Season the cutlets, 8 pieces in total, with salt and pepper. Coat chicken in flour, then egg, then breadcrumbs and reserve.
Heat a couple of inches of water in a covered pot. Trim up the cauliflower and halve when slice into 1 inch thick slices or break into florets. Arrange cauliflower in boiling water and season with salt. Cover and cook 3-4 minutes, then drain the cauliflower and arrange in a small shallow casserole dish.
Heat a small sauce pot over medium heat. Melt butter, whisk in flour, cook 1 minute then whisk in milk, season with salt, pepper and nutmeg; thicken for 3-4 minutes. Stir the Fontina cheese and the sage into the sauce and melt, about 1 minute. Pour the sauce over the cauliflower to cover evenly, top with remaining 1/2 cup parmigiano cheese and a sprinkle of parsley. Bake 30 minutes until golden brown and bubbly.
Heat 1/2 inch olive oil and shallow fry the cutlets 3-4 on each side in 2 batches. Reserve the cooked cutlets on rack placed over baking sheets. Serve 2 cutlets per person with a wedge of lemon along side and lots of cauliflower as a side dish.