Well, if a lab grown steak:
A) Has the same nutritional value as a real steak (or even better!?),
B) Has the same cooking/flavor properties...
As compared to real meat/steaks... Then...
Culinary arts doesn't change that much! You won't notice much of a difference in the world of food, I would think.
People would just keep making the same meals they've always made, and also exploring new meals/dishes, as humans have always done as a species.
In such a world, separate vegetarian/vegan dishes would also continue to get made because they have some unique flavor profiles that people enjoy.
For example:
I eat meat a couple of times per week, but also lots of vegetarian/vegan dishes too, including some awesome Indian-style dishes that my GF has learnt to cook lately... because...
It's f'cking good! Tastes great!
That's why! No other reason.
Likewise:
Sometimes I want a peperoni pizza.
Sometimes I want a vegetarian pizza.
Both types of pizza are enjoyable in their own ways and have unique flavor profiles I don't want to give up.
Likewise: sometimes I want a nice pasta with an amazing flavored sauce, and that's it. Nice and simple. Other times I want some meat in my pasta meal!
This type of thing would just simply continue as always.
In the end:
You're NOT going to erase hundreds of thousands of years of human culinary arts experience just because some meats can be grown in the lab.
Our classic dishes will simply utilize the new source of meat (lab grown) if that meat's taste profile, texture, nutrition, and cooking properties remain the same.
If not, then new recipes will be invented specific to the lab grown meat! And some of those recipes will have a very unique new taste to enjoy as well!
So that will just add more variety of dishes for you to try and enjoy!