I'm retired and many times daily lunch is an impromptu matter. Leftovers are not discarded if they are recent and not enough for another complete meal.
I recently made chicken paprikash for dinner, and a frittata for lunch the next day. The latter was too filling to completely devour at one sitting. The frittata was made with 8 scrambled eggs surrounding cubes of leftover meatloaf, leftover cubes of Genoa salami intended as a salad addition, cooked acini di pepe and topped with a combination of grated provolone and mozzarella melted on it after being removed from under the broiler. The next day I removed the leftover half of frittata from the fridge and cubed it. I spooned the leftover paprikash over the cubes and microwaved the concoction. it was a very tasty lunch.
Another concoction was leftover Texas Hash added to homemade minestrone denso. The hash recipe is available by using its name as keywords for a search engine. The minestrone is like a thick stew. The mixture of the two was also a very tasty lunch.
I follow Mario Batali's dictum, "Italians never waste anything that can be used as food." Comunque, i miei antenati non erano italiani.
Does anyone else in Chowhound Land do some mixing of leftovers to concoct another meal?