I am odd by MN vegan standards as I like 'mock meat'. I like the normal aspect of it, being able to eat something just like everyone else is getting instead of something that has others going 'ooh what's that' at me (I don't like attention on me while I eat).
One of my favourite cheap meals out is the wetherspoons/yates/usual chain pub option of a 'beyond burger'. I usually get it with a baked potato instead of chips, to be a little more healthy and more satiated.
The Ivy do the same, but with nicer garnishes and for a lot more £, but the chips there are much nicer so I do go for them.
There are some great 'normal food' vegan options at the Head of Steam (I've only been to the Leeds one) too.
I've also had vegan breakfasts in chain pubs that have really hit the spot! Great for if you're about to go out for several or more drinks.
Ostello Lounge does some great vegan/vegetarian dishes-the flatbreads are delicious.
Having said that and made myself sound like a lout, I do like more traditional, better quality food for occasions.
The best 'naice' vegan food I've had a draw between Corarima https://www.corarima.co.uk, Eritrean dishes, I don't remember what it were called but between four of us we ordered two platters, each with lots of small delicious dishes, and Gran Cru Birkenshaw-I ring ahead and the chef's always more than willing to make me a bespoke dish.