Depends on what sort of meals you're really looking for. I was never a big fan of all of these tousled-up Instagram Meals that need 20 obscure ingredients from 20 different specialist shops, so all of my meals tend to be alarmingly basic with the exception of any spices that I use to make them not wind up tasting like wet cardboard.
Generally speaking, you're hard-pressed to turn chicken, broccoli and rice into a high-calorie meal if you still to broiling and finding different ways to season it that don't involve butter or deep-frying. Asian and Cajun spices in particular can really turn an otherwise boring pile of chicken into something very interesting without adding any mention-worthy amount of calories to it. The same can be said for low-calorie wraps
(I've found some as low as 60 per), which rapidly became my go-to replacement for sandwich bread if I got tired of making sandwiches. There's also plenty of bread out there that goes as low as 45 calories per slice, though.
Oatmeal and tuna are easily a staple of my everyday diet, too. Nearly every single breakfast I've made for the past such-and-such years has been 1/2 cup of oatmeal, 1 cup of water, 1 tbsp. of peanut butter, 1 tsp. of honey, and a dash of cinnamon. Whole thing measures out around 300 calories, and if that doesn't feel like enough then I'll add an egg somewhere in there. You don't have to relegate it to just breakfast, though. I'm not sure when exactly that oatmeal became nothing more than a mushy breakfast food, but there's
loads of different ways that you can use it. One of my favorites has always been
oatmeal-tuna 'hamburgers' or pan-frying oatmeal and eggs, which comes out tasting
alarmingly similar to hash browns.
You shouldn't discount eggs, either. Eggs are hands-down one of the most-versatile foods available and even if
all you have to work with is a box of eggs and a frying pan, there's still dozens of ways to cook them right there in front of you. I always keep about a half-dozen boiled eggs just sitting in the fridge at any given time purely because they're about 75 calories each. Tuna's kind of the same way, there's a load of things you can do with even just canned tuna, and like I mentioned much earlier "up-thread", even after I completely changed my diet years ago, I never got rid of my tuna melts, I just
changed the recipe so they weren't horrifyingly high-calorie.
Never try to maintain a 'diet' that you hate, you're just dooming yourself to failure. Just take existing foods that you already love and find a way to meet them halfway with a lower-calorie alternative. Pizza, cookies, pasta, ice cream, it doesn't matter, there's
always a way to find or make an alternative that's still the original food you enjoyed without it having to be 600 calories a shot. It'll taste a little different, my tuna melts definitely changed, but once you acclimate to that difference then you're all set. It's a bit like when people stop drinking soda or switch to a zero-calorie soda: They fucking
hate it at first, but after a month or two they try the original soda again and wind up gagging.
If you'd find it helpful: I actually keep a calorie log for all the foods that I eat. They don't have macro/micro nutrients listed and it doesn't exactly come with recipes, but it could give you an indication of the sorts of food that I eat on a low-to-mid calorie diet when I'm not on a higher-calorie "bulk", and believe me when I say that even though I stay under 2,000 calories, it's not exactly restrictive when it comes to the variety that I eat. I'm something of a protein shake addict though, so if you can ignore the 200-500 calories in what amounts to a meal replacement shake every day, you'll find quite a bit of wiggle room to work with.