The good news is all your regular meals translate really easily to adding veg.
Korma - add veg (green pepper and onion are the obvious starting point). Make a mild veg curry instead (I’d roast veg from the veg box with curry spices - butternut squash, sweet potato, carrot, aubergine, pepper, onion, tomatoes would all work well just pick what appeals to you, and then chuck in a tin of coconut milk, a squeeze of lime and serve with a sprinkle of chopped coriander and chilli if you fancy. Or serve a smaller portion of your usual curry with a veggie side dish. Loads of Indian veggie dishes to choose from.
Spag Bol - start with a mirepoix (a finely chop carrot, onion and celery base). You can buy this very cheaply pre chopped and frozen - some stores will label it vegetable base or county vegetable mix. Add in finely chopped mushrooms and peppers (I like red, yellow or orange for this). Use a tin of tomatoes not a jarred sauce. You’ll have a couple of servings of veg per portion. You can also use this for lasagna, and serve with a side salad (salad doesn’t have to be leaves or tomatoes if you don’t like them). There’s also loads of vegetable lasagna’s to try.
Chilli. As with the spag Bol I’d use onions, peppers and mushrooms, tinned tomatoes and kidney beans. You could also try adding a tin of sweetcorn, grated carrot and/or making a four bean chilli. If you like chilli would you like something like fajitas? There’s a tray bake version with onions, peppers and steak that’s really quick and easy.
Pizza - veggie feast! Ok it’s still going to be mostly cheese and bread but honestly you can put pretty much any veg on a pizza. Serve with a salad or slaw of some sort or crudités and a dip or two.
Burgers - loads of veggie burgers you can make, or falafel? Again salads and slaws on the side.