When cooking for one, you end up with a lot of leftovers especially if, like me, you make big pots of some dishes. When my freezer fills up to a certain point, I stop cooking and start putting together the odds and ends and come up with meals.
I try not to have too many desserts in my freezer, cause I snack when I'm bored, so I give away as much as I can of the more successful results. But this means I get stuck with some things that aren't suitable for gifting. Like a tray of peach crumble bars that were mostly crumble and very little peach. A while back, I bought a clamshell of mostly bruised and tasteless peaches that I had to throw away. So I ended up with a lot less fruit than I needed ... which I didn't realize until I was in the middle of baking with nothing else to add in to make up the shortage. A bit of apricot jam (ran out of ice cream) is making the bars a bit more palatable, at least.
Right now, I'm adding soup as often as I can to my meals. Biscuits or bread are a good filler.
Of course, I DO make new dishes. I snagged a double package of sausage filled tortellini on sale and cooked one up in a blush sauce. On its own, the pasta dish isn't very filling, and I didn't have any greens for salad in the house, so I served it with a savoury plate of polenta.
The rest of the polenta was patted out into a buttered 8" by 8" glass dish and refrigerated, prior to being fried up as a base for a jarred spaghetti-pesto sauce.
Chicken drumsticks are often found on sale. A bit of Italian seasoning sprinkled on top and unattended baking time and you've got the start of a great meal.
A bit of barbecue sauce and a different starch, and you've got a new meal.
Things get a bit tight just before payday or in the case of supply teachers, with no paycheques for 3 months, so a tuna macaroni salad with pasta and canned tuna bought on sale is filling and tasty too. I'd usually throw some diced celery into my salad but in this case, diced raw carrots made for a nice, crunchy bite and a bit of colour too.
Whenever I have coleslaw in the house, I'm tempted to make okonomiyaki, a Japanese pancake. Another inexpensive and filling dish.