In a small pot, melt the butter with a splash of oil over low heat. Lightly fry the pancetta, making sure not to burn the butter. Add the onion, garlic, red bell pepper, and carrot, and sauté. Add the spinach, stir, cover, and cook for 1 minute.

Add the flour and cook for about 2 minutes over low heat, stirring occasionally so it doesn't stick to the pot. Pour in the milk and salt, mix well, and cook for a couple of minutes, stirring so it doesn't stick. Place the spinach mixture in the refrigerator to cool.

To assemble the crepes: Lay the crepes out on the table. On the lower half of each crepe, spread the spinach filling and place a rolled slice of cheese on top. Roll up the crepes and place them in a buttered baking dish. Cover the center of the crepes with bechamel sauce, sprinkle with the cheese strips and Parmesan cheese. Place in the oven with the broiler on to brown the crepes.