It is such a well-known dish, there is almost no need for a recipe. You can use different fillings for the rolled chicken, such as half-cooked rice, diced vegetables, any type of deli style meat product or only spinach. The preparation process is always the same: using the meat mallet, flatten the breast as thin as possible to roll it out easily. While doing this, I use a small bag to keep my kitchen clean. However you can buy them ready from your butcher if he does not mind flattening them for you.
You need half a breast per person, enough spinach leaves to cover the breasts and very thinly sliced jambon. The cheese stick is gruyere here but you can choose any type of hard cheese. Just lay the breast down, salt and pepper it, cover with a couple of spinach leaves. Do not forget to sprinkle with ground nutmeg, it is the best friend of spinach! Lay one slice of jambon over the leaves and put the cheese stick at the wide end of the breast.
Before rolling the chicken, pour cornmeal in a plate, breadcrumbs in another and brake two eggs in a third one. Sprinkle the egg with some blackpepper and salt, mix well. Roll the breast tightly and tuck the sides closely inside. Holding firmly, dip it in the cornmeal first, roll to cover throughly, do not forget to dip the narrow ends. Then dip in the egg mixture and cover completely. Finely roll it in breadcrumbs and set aside. After finishing with all the pieces, put them in the fridge, uncovered, for at least half an hour to harden and drying-up. You can prepare them ahead and keep refrigerated all day.
30 mins before serving, heat the oven at 200C degrees. Put a little olive oil in a non-stick pan and fry rolls on all sides until golden. Place a wire rack on your tray and put the fried rolls on it. Juices will be dripping, so you can add a little water in the tray just to make the clean-up easier.
Bake them, in preheated oven for 10 minutes to cook throughly. Do not keep them overtime in the oven, the cheese would melt away and may spill out by the heat. Remove from the oven and serve immediately. Leftovers (if you would have any!) would make good sandwiches, sliced thinly and accompanied by mustard and some lettuce leaves. Enjoy!