We're out over lunch time, but I often do things with our evening meal that will either reduce or eliminate cooking for the following evening, or bung something in the freezer so this could translate into a lunch/evening meal for the following day too.
Cook double quantity bolognese to go with pasta, then add chopped fresh chilli to the extra portions, leave in the fridge over night, then have with either rice and tortilla chips, or jacket potato and salad the following day.
Buy a larger meat joint than we need, then have the extra meat wither cold with salad/in wraps, or with stir fried vegetables and noodles (depending on what the meat is). I sometimes pop a marinade on the meat before it goes in the fridge too.
Cook a portion and a half of meatballs with spaghetti for the first meal, then make meatball subs with the half portion the following day.
Spicy marinated chicken with rice and veggies, then use the leftover chicken with salad and cous cous/quinoa for the next meal.
If I do a cooked breakfast, I do extra sausage, bacon, mushrooms & tomato and make it into a breakfast quiche. Usually I do a couple of extra quiches to bung in the freezer as well while I'm at it.
I do diced beef in gravy with veggies and dumplings in the slow cooker (I know you don't have one, but a pan would do, or perhaps invest?), then put the excess in a pie crust, and bake along with some roast vegetables for the following meal.
If I ever make a lasagne, I make extra white sauce, and keep half back for mac & cheese for another meal. I just grate cheese in before heating the sauce through while the pasta boils.
I do a deconstructed fish pie, so I cook the fish and sauce on a dish, but do double quantity. I then make mash (also double quantity) to blob on top of the fish when I plate up. The rest gets mixed in with the fish, and rolled in egg and breadcrumbs to make fishcakes.
If I make a soup that I'll be serving twice in short succession, I'll do it once with hot buttered rolls, then the next time with grilled cheese pittas cut into fingers so it feels a bit less samey. Or I sometimes spice the second portion so it tastes different.
Hopefully that might offer some ideas/inspiration 