Boost high protein drink is a great balanced meal - especially when you do not actually feel like eating (believe it or not, the first couple of days may find you with a low appetite).
I have taken to making smoothies from bananas and seasonal fruits (breakfast), I get protein lunch time by drinking Fat free chicken broth and if you make some really smooth mashed potatoes, you can mix a little in to the broth and hopefully still be able to drink it through a straw if that is what you are going to need.
Be careful not to fall into the milk shake trap, they can be so good but are usually so very bad for a diet - a couple of milk shakes can easily use your entire food allowance for the day!
You may want to invest in a juicer as opposed to simply a blender, depending on how long you are going to have to drink through a straw.
As for me, I was able to semi-chew some frozen corn and peas gently cooked - good quality vegetables meant that I was able to at least squash them between my teeth if not properly chew them completely - tomorrow (Friday) is exactly a week since my surgery so I think that I am doing pretty well even if I do get frustrated at times.
Today I simmered some finely chopped spinach, squash and herbs in chicken broth, then used a blender to blend out the lumps - that made a great lunch.
Use your imagination and see what you can come up with as the fancy takes you.
Good luck and keep us updated on the surgery - we care ! Will let you know if I think of anything else