750 calories a serving is not that much, especially for dinner and if you're generally active throughout the day. I need the calories to play sports, run, lift weights or otherwise be active. I can rip through 1,000 calories pretty easily after playing a sport.
If you don't need 750 calories, that's fine, just save a portion of the dish to eat later.
It's quite a bit and most people aren't active. You could probably do 1,000 calories if you played intense basketball or soccer for an hour, but not much else. Running yes sure, but again that one 750 calorie meal for around an hour of exercise, even running or lifting weights, would at most put you back to a state of "I haven't consumed calories today" aside from your metabolic rate. So then you have to eat for the little things you do, say, walk to work, or sharpen pencils or whatever, plus your metabolic rate. That's most likely not this "generic 2,000 calorie diet" but something above or below that.
I've seen some comments about "well it's not much if you just spread out your calories by eating 750-250-1000" or whatever, but that's nonsense. You don't justify eating a large cheese pizza once/day because it's 2,000 calories and call yourself healthy. I mean, after all you did a 0-0-2000 split and hey that's under 2000!
If you don't need 750 calories, that's fine, just save a portion of the dish to eat later.